**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
#include "bits/stdc++.h"
#ifndef ONLINE_JUDGE
#include "headers/debug.h"
#else
#define debug(...) 42
#endif

using namespace std;

#define all(x) x.begin(), x.end()
#define ff first
#define ss second
#define LLINF 0x3f3f3f3f3f3f3f3f
#define INF 0x3f3f3f3f
#define uniq(x) sort(all(x)); x.resize(unique(all(x))-x.begin());
#define sz(x) (int)x.size()
#define pw(x) (1LL<<x)
#define pb push_back
#define int long long

using pii = pair<int, int>;
using ll = long long;
using ld = long double;
const ll MOD = 1e9 + 7;
const long double PI = acos(-1.0);

int mult(int a, int b) {
	a %= MOD;
	b %= MOD;
	return a*b%MOD;
}
int bin_pow(int a, int p) {
	if (p == 0) return 1;
	if (p & 1) return mult(a, bin_pow(a, p-1));
	int x = bin_pow(a, p/2);
	return mult(x, x);
}
int rev(int x) {
	return bin_pow(x, MOD - 2);
}

void solve() {
	int n; cin >> n;
	vector<int> a(n+1), p(n+1);
	for (int i=1; i<=n; i++) cin >> a[i];
	for (int i=1; i<=n; i++) cin >> p[i];
	int z = rev(10000);
	vector<int> livep(1025), diep(1025, 1);
	for (int i=1; i<=n; i++) {
		int v = a[i];
		int newlive = mult(livep[v], 10000-p[i]) * z % MOD + mult(diep[v], p[i]) * z % MOD;
		int newdie = mult(livep[v], p[i]) * z % MOD + mult(diep[v], 10000-p[i]) * z % MOD;
		newlive %= MOD;
		newdie %= MOD;
		livep[v] = newlive;
		diep[v] = newdie;
	}
	vector<int> dp(1025);
	dp[0] = 1;
	for (int i=1; i<=1023; i++) {
		vector<int> newdp(1024);
		for (int j=0; j<=1023; j++) {
			newdp[j^i] += dp[j] * livep[i]; newdp[j^i] %= MOD;
			newdp[j] += dp[j] * diep[i]; newdp[j] %= MOD;
		}
		swap(dp, newdp);
	}
	int ans = 0;
	for (int i=1; i<=1023; i++) {
		int v = i*i*dp[i]%MOD;
		ans += v; ans %= MOD;
	}
	cout << ans << '\n';
}

int32_t main() {
	ios::sync_with_stdio(0), cin.tie(0);
	int t = 1; cin >> t;
	while(t--)
		solve();
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
1
1
5000
2
1 1
5000 5000
2
1 2
5000 5000
3
1 2 3
5000 5000 5000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
from sys import stdin
input = lambda: stdin.readline().rstrip()
MOD = 1000000007
l = pow(10000, -1, MOD)

def solve1(p, u):
    dp = [[0] * 1025 for _ in range(4)]
    dp[0][0] = 1
    for i in range(1024):
        v = (i >> u) & 1
        for k in range(2):
            dp[k][i + 1] = (dp[k][i] * (1 - p[i]) + dp[k ^ v][i] * p[i]) % MOD
    return dp[1][1024]

def solve(p, x, y):
    dp = [[0] * 1025 for _ in range(4)]
    dp[0][0] = 1
    for i in range(1024):
        v = (i >> x & 1) * 2 + (i >> y & 1)
        for k in range(4):
            dp[k][i + 1] = (dp[k][i] * (1 - p[i]) + dp[k ^ v][i] * p[i]) % MOD
    return dp[3][1024]

def main():
    n = int(input())
    p = [0] * 1024
    for x, y in zip(map(int, input().split()), map(int, input().split())):
        res = y * l % MOD
        p[x] = (p[x] * (1 - res) + (1 - p[x]) * res) % MOD

    ans = 0
    for i in range(10):
        ans = (ans + solve1(p, i) * (1 << (i * 2))) % MOD
        for j in range(i + 1, 10):
            ans = (ans + solve(p, i, j) * (1 << (i + j + 1))) % MOD
    return ans

for _ in range(int(input())):
    print(main())

# from sys import stdin
# input = lambda: stdin.readline().rstrip()
# mod = 1_000_000_007
# fenmu2 = pow(10000, -1, mod)

# def solve():
#     n = int(input())
#     p = [0] * 1024
#     for x, y in zip(map(int, input().split()), map(int, input().split())):
#         res = y * fenmu2 % mod
#         p[x] = (p[x] * (1 - res) + (1 - p[x]) * res) % mod

#     ans = 0
#     for i in range(10):
#         for j in range(10):
#             dp = [1, 0, 0, 0]
#             ndp = [0, 0, 0, 0]
#             for k in range(1024):
#                 v = (k >> i & 1) * 2 + (k >> j & 1)
#                 for idx in range(4):
#                     ndp[idx] = (dp[idx] * (1 - p[k]) % mod + dp[idx ^ v] * p[k] % mod) % mod
#                 for idx in range(4):
#                     dp[idx], ndp[idx] = ndp[idx], 0
#             ans += (1 << (i + j)) * dp[3]
#             ans %= mod
#     return ans

# for _ in range(int(input())):
#     print(solve())

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
2
1
1
10000
2
1023 1023
10000 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import sys
from bisect import *
from collections import *
from heapq import *
lambda input: sys.stdin.readline().rstrip()
li = lambda type: list(map(type, input().split()))

MOD, bits = 10**9+7, 11
inv = pow(10000, MOD-2,MOD)
for _ in range(int(input())):
    N = int(input())
    dp0, dp = [0] * (1<<10), [0] * (1<<10)
    dp[0] = 1
    for a,p in zip(li(int), li(int)):
        for k in range(1<<10):
            dp0[k] = (dp[k]*(10000-p) + dp[k^a]*p)%MOD
        dp,dp0 = dp0,dp
    ans = sum([i*i*dp[i] for i in range(1<<10)])%MOD*pow(inv, N,MOD)%MOD
    print(ans)

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
1
1
10000
2
1 2
1 9999
2
1 1
1 10000
3
1 2 3
10000 1 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
MOD = 10**9 + 7
INV_10K = pow(10000, MOD-2, MOD)

def modinv(a, m):
    return pow(a, m - 2, m)

def solve():
    import sys
    input = sys.stdin.read
    data = input().split()

    idx = 0
    t = int(data[idx])
    idx += 1
    results = []

    for _ in range(t):
        n = int(data[idx])
        idx += 1

        a = list(map(int, data[idx:idx+n]))
        idx += n

        p = list(map(int, data[idx:idx+n]))
        idx += n

        # Initialize dp arrays
        max_xor = 1024
        dp = [[0] * max_xor for _ in range(n+1)]
        dp[0][0] = 1

        for i in range(1, n+1):
            prob = p[i-1] * INV_10K % MOD
            inv_prob = (1 - prob + MOD) % MOD

            for j in range(max_xor):
                dp[i][j] = (dp[i-1][j] * inv_prob + dp[i-1][j ^ a[i-1]] * prob) % MOD

        expected_value = 0
        for j in range(max_xor):
            expected_value = (expected_value + dp[n][j] * j * j) % MOD

        results.append(str(expected_value))

    print("\n".join(results))

if __name__ == "__main__":
    solve()

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
To generate a challenging test input that exposes the bug in the given code, we need to consider edge cases and scenarios that might cause the algorithm to fail. Here are some key points to consider:

1. **Edge Cases**:
   - **Empty Set**: Test with an empty set to ensure the code handles it correctly.
   - **Single Element**: Test with a single element to check if the code can handle simple cases.
   - **All Elements with the Same Value**: Test with all elements being the same to see if the code can handle uniform input.
   - **All Elements with Different Values**: Test with all elements being different to ensure the code can handle diverse input.
   - **All Probabilities are 0 or 10000**: Test with probabilities that are either 0 or 10000 to check if the code can handle extreme cases.

2. **Complex Cases**:
   - **Mixed Probabilities**: Test with a mix of probabilities to ensure the code can handle intermediate values.
   - **Large XOR Values**: Test with values that have a high XOR value to ensure the code can handle large numbers.

Given these considerations, here is a small-scale test input that includes a mix of these scenarios:

```plaintext
5
1
1
10000
2
1 2
5000 5000
3
1 2 3
1000 2000 3000
4
1 2 3 4
0 5000 10000 7500
5
1 2 3 4 5
10000 0 10000 0 10000
```

This test input includes:
1. A single element with a probability of 100%.
2. Two elements with a probability of 50% each.
3. Three elements with different probabilities.
4. Four elements with mixed probabilities, including 0% and 100%.
5. Five elements with alternating probabilities of 0% and 100%.

This variety of test cases should help expose any bugs in the given code.


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import java.util.Scanner;

public class ExpectedPower {
	static long mod = (long)1e9 + 7;

	private static long qpow(long x, long y) {
		long res = 1;
		while(y != 0) {
			if((y & 1) == 1) {
				res = res * x % mod;
			}
			x *= x;
			x %= mod;
			y >>= 1;
		}
		return res;
	}

	private static long inv(long x) {
		return qpow(x, mod - 2);
	}

	private static long mo(long x) {
		return (x % mod + mod) % mod;
	}

	static Scanner sc = new Scanner(System.in);
	static long inv1e4 = inv(10000);
	public static void main(String[] args) {
		int t = sc.nextInt();
		while(t-- > 0) {
			int n = sc.nextInt();
			int[] A = new int[n + 1];
			long[] P = new long[n + 1];
			for(int i = 1; i <= n; i++) {
				A[i] = sc.nextInt();
			}
			for(int i = 1; i <= n; i++) {
				P[i] = sc.nextLong();
				P[i] = P[i] * inv1e4 % mod; // pi/1e4 = pi * inv(1e4)
			}
			long res = solve(A, P);
			System.out.println(res);
		}
	}

	private static long solve(int[] A, long[] P) {
		int n = A.length - 1;
		long[][] f = new long[2][1024]; // [0] => [1] => [0]...
		f[0][0] = 1;
		for(int i = 1; i <= n; i++) {
			int sel = i & 1;
			int pre = 1 - sel;
			long np = mo(1 - P[i]);
			for(int j = 0; j < 1024; j++) {
				f[sel][j] = 0;
				f[sel][j] = (f[sel][j] + (f[pre][j] * np % mod)) % mod;
				f[sel][j] = (f[sel][j] + (f[pre][j ^ A[i]] * P[i] % mod)) % mod;
			}
		}
		long res = 0;
		int last = n & 1;
		for(int j = 0; j < 1024; j++) {
			res += f[last][j] * j * j % mod;
			res %= mod;
		}
		return res;
	}
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
1
2
1 1
10000 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import java.util.Scanner;

public class ExpectedPower {
	static long mod = (long)1e9 + 7;

	private static long qpow(long x, long y) {
		long res = 1;
		while(y != 0) {
			if((y & 1) == 1) {
				res = res * x % mod;
			}
			x *= x;
			x %= mod;
			y >>= 1;
		}
		return res;
	}

	private static long inv(long x) {
		return qpow(x, mod - 2);
	}

	private static long mo(long x) {
		return (x % mod + mod) % mod;
	}

	static Scanner sc = new Scanner(System.in);
	static long inv1e4 = inv(10000);
	public static void main(String[] args) {
		int t = sc.nextInt();
		while(t-- > 0) {
			int n = sc.nextInt();
			int[] A = new int[n + 1];
			long[] P = new long[n + 1];
			for(int i = 1; i <= n; i++) {
				A[i] = sc.nextInt();
			}
			for(int i = 1; i <= n; i++) {
				P[i] = sc.nextLong();
				P[i] = P[i] * inv1e4 % mod; // pi/1e4 = pi * inv(1e4)
			}
			long res = solve(A, P);
			System.out.println(res);
		}
	}

	private static long solve(int[] A, long[] P) {
		int n = A.length - 1;
		long[][] f = new long[2][1024]; // [0] => [1] => [0]...
		f[0][0] = 1;
		for(int i = 1; i <= n; i++) {
			int sel = i & 1;
			int pre = 1 - sel;
			for(int j = 0; j < 1024; j++) {
				f[sel][j] = 0;
				f[sel][j] += f[pre][j] * mo(1 - P[i]) % mod;
				f[sel][j] %= mod;
				f[sel][j] += f[pre][j ^ A[i]] * P[i] % mod;
				f[sel][j] %= mod;
			}
		}
		long res = 0;
		int last = n & 1;
		for(int j = 0; j < 1024; j++) {
			res += f[last][j] * j * j % mod;
			res %= mod;
		}
		return res;
	}
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
1
1
10000
2
1 2
10000 10000
3
1 2 3
10000 10000 10000
4
1 2 3 4
10000 10000 10000 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
// Problem: E. Expected Power
// Contest: Codeforces - Codeforces Round 976 (Div. 2) and Divide By Zero 9.0
// URL: https://codeforces.com/contest/2020/problem/E
// Memory Limit: 256 MB
// Time Limit: 4000 ms
// This Code is written By Anas_Da
//
// Powered by CP Editor (https://cpeditor.org)

#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define cy cout<<"YES\n";
#define cn cout<<"NO\n";
#define c1 cout<<"-1\n";
#define all(x) x.begin(),x.end()
#define re(x) x.rbegin(),x.rend()
#define F first
#define S second
#define ii pair<ll,ll>
#define IOS ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
ll x,n,m,k;
string s;
vector<ll>vec;
set<ll>st;
map<ll,ll>mp;

ll MOD=1e9+7;
ll GCD(ll x,ll y)   {   return y ? GCD(y,x%y) : x ;   }
void _clear(){

}

///////POWERMOD

ll power(ll x, ll y, ll m = MOD) {
	ll res = 1;
	for (int i = 0; (1LL<<i) <= y; i++, x = x * x % m)
		if (y & 1LL << i)
			res = res * x % m;
	return res;
}

void solve(int tc){
	cin>>n;
	ll arr[n+1],p[n+1];
	for(int i=1;i<=n;i++){
		cin>>arr[i];
	}
	ll inv=power(10000,MOD-2)%MOD;
	for(int i=1;i<=n;i++){
		cin>>p[i];

	}
	vector<int>dp(1024);
	dp[0]=1;
	for(int i = 1; i <= n; i++){
            vector<int> ndp(1024);
            for(int j = 0; j < 1024; j++){
                ndp[j ^ arr[i]] += (ll)dp[j] * p[i] % MOD * inv % MOD;
                ndp[j] += (ll)dp[j] * (10000LL - p[i]) % MOD * inv % MOD;
                if(ndp[j ^ arr[i]] >= MOD) ndp[j ^ arr[i]] -= MOD;
                if(ndp[j] >= MOD) ndp[j] -= MOD;
            }
            swap(dp, ndp);
        }
	ll Ans=0;
	for(ll i=0;i<1024;i++){
		Ans+=i*i*(ll)dp[i]%MOD;
		if(Ans>=MOD)Ans-=MOD;
	}
	cout<<Ans<<'\n';

}
int main()
{
    IOS
    int t=1;
    cin>>t;
    for(int i=1;i<=t;i++){
       _clear();
       solve(i);
    }
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
1
1
10000
2
1 1
10000 10000
3
1 1 1
10000 10000 10000
4
1 2 3 4
10000 10000 10000 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
#include<bits/stdc++.h>

#define int long long
using namespace std;
const int mod=1e9+7;
int arr[2000009];
int brr[2000009];
int dp[1034][3];

int qimi(int a,int b)
{
   int res=1;
   while(b)
   {
      if(b&1) res=res*a%mod;
      a=a*a%mod;
      b>>=1;
   }
   return res;
}

signed main()
{
     int niyuan=qimi(10000,mod-2);
    int tt=0;
    scanf("%lld",&tt);
    while(tt--)
    {
       int n;
       scanf("%lld",&n);
       for(int i=1;i<=n;i++)
       {
          scanf("%lld",&arr[i]);
       }
       for(int i=1;i<=n;i++)
       {
          scanf("%lld",&brr[i]);
       }
       int cur=0;
       for(int i=0;i<=1023;i++)
       {
          dp[i][cur]=0;
       }
       dp[0][cur]=1;
       for(int i=1;i<=n;i++)
       {
          cur^=1;
          for(int j=0;j<=1023;j++) dp[j][cur]=0;
          for(int j=0;j<=1023;j++)
          {
             dp[j][cur]+=dp[j][cur^1]*((1-brr[i]*niyuan%mod+mod)%mod)%mod;
             dp[j][cur]%=mod;
             dp[j^arr[i]][cur]+=dp[j][cur^1]*(brr[i]*niyuan%mod)%mod;
             dp[j^arr[i]][cur]%=mod;
          }
       }
       int ans=0;
       for(int i=1;i<=1023;i++)
       {
           //printf("cur:%lld\n",dp[cur][i]);
          ans+=i*i%mod*dp[i][cur]%mod;
          ans%=mod;
       }
       printf("%lld\n",ans);
    }
    return 0;
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
1
10
1 2 3 4 5 6 7 8 9 10
10000 10000 10000 10000 10000 10000 10000 10000 10000 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
#!/usr/bin/env python
import os
import sys
from io import BytesIO, IOBase

def extended_gcd(a, b):
    """returns gcd(a, b), s, r s.t. a * s + b * r == gcd(a, b)"""
    s, old_s = 0, 1
    r, old_r = b, a
    while r:
        q = old_r // r
        old_r, r = r, old_r - q * r
        old_s, s = s, old_s - q * s
    return old_r, old_s, (old_r - old_s * a) // b if b else 0

def modinv(a, m):
    """returns the modular inverse of a w.r.t. to m, works when a and m are coprime"""
    g, x, _ = extended_gcd(a % m, m)
    return x % m if g == 1 else None

def main():
    MOD = 10 ** 9 + 7
    DEN = modinv(10 ** 4, MOD)

    t = int(input())

    for _ in range(t):
        n = int(input())
        a = [int(ai) for ai in input().split()]
        p = [(int(pi) * DEN) % MOD for pi in input().split()]

        curr = [0] * 1024
        curr[0] = 1

        for ai, pi in zip(a, p):
            prev, curr = curr, [0] * 1024
            for i in range(1024):
                curr[i] = prev[i] * (1 - pi) + prev[i ^ ai] * pi

        sol = 0
        for i in range(1024):
            sol = (sol + (i ** 2) * curr[i]) % MOD

        print(sol)

# region fastio

BUFSIZE = 8192

class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._file = file
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)

class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")

sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")

# endregion

if __name__ == "__main__":
    main()

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import sys
input = sys.stdin.readline
from collections import deque

MOD = 10**9 + 7

def ii():
    return int(input())

def lii():
    return [int(x) for x in input().split()]

DIV10000 = pow(10000, -1, MOD)

def solve():
    n = ii()
    a = lii()
    p = lii()

    #dp[i][j][00, 01, 10, 11]

    dp = [[[1,0, 0, 0] for i in range(10)] for j in range(10)]
    for i in range(n):
        curr = a[i]
        prob = p[i]*DIV10000
        invprob = MOD+1-prob
        bits = [0]*10
        bit = 0
        while curr:
            bits[bit] = curr & 1
            curr >>= 1
            bit += 1

        for j in range(10):
            for k in range(10):
                temp = [0]*4
                for l in range(4):
                    temp[l] = (dp[j][k][l]*(invprob) % MOD + dp[j][k][l^bits[j]^(bits[k]*2)]*prob % MOD) % MOD

                dp[j][k] = temp

    ans = 0
    for i in range(10):
        for j in range(10):
            ans = (ans + (dp[i][j][3])*(1 << (i+j))) % MOD

    return ans

tc = ii()
for _ in range(tc):
    print(solve())

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
3
1
1023
10000
2
1 2
1000 9000
3
1 2 3
1000 5000 9000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import java.util.*;

public class Main {
    static final int MOD = 1_000_000_007;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        // Input size of array
        int t = sc.nextInt();
        while(t-- > 0) {
        int n = sc.nextInt();

        // Input arrays
        int[] a = new int[n];
        int[] p = new int[n];
        for (int i = 0; i < n; i++) a[i] = sc.nextInt();
        for (int i = 0; i < n; i++) p[i] = sc.nextInt();

        // Solve the problem
        System.out.println(calculateExpectedXORSquared(n, a, p));
    }
}

    static long calculateExpectedXORSquared(int n, int[] a, int[] p) {
        // Probability array (converted to modular arithmetic)
        long[] prob = new long[n];
        for (int i = 0; i < n; i++) {
            prob[i] = (p[i] * modInverse(10_000, MOD)) % MOD;
        }

        // Sparse DP: Use two HashMaps for current and next states
        Map<Integer, Long> dp = new HashMap<>();
        dp.put(0, 1L); // Base case: XOR = 0 with probability 1.

        // Fill DP table
        for (int i = 0; i < n; i++) {
            Map<Integer, Long> next = new HashMap<>();

            for (Map.Entry<Integer, Long> entry : dp.entrySet()) {
                int currentXOR = entry.getKey();
                long currentProb = entry.getValue();

                // Exclude a[i]
                next.put(currentXOR, (next.getOrDefault(currentXOR, 0L) + currentProb * (MOD + 1 - prob[i]) % MOD) % MOD);

                // Include a[i]
                int newXOR = currentXOR ^ a[i];
                next.put(newXOR, (next.getOrDefault(newXOR, 0L) + currentProb * prob[i] % MOD) % MOD);
            }

            dp = next; // Move to the next state
        }

        // Compute expected value of (f(S))^2
        long result = 0;
        for (Map.Entry<Integer, Long> entry : dp.entrySet()) {
            int x = entry.getKey();
            long probX = entry.getValue();
            result = (result + probX * x % MOD * x % MOD) % MOD;
        }

        return result;
    }

    // Modular inverse using Fermat's Little Theorem
    static long modInverse(long a, int m) {
        return modPower(a, m - 2, m);
    }

    // Modular exponentiation
    static long modPower(long base, long exp, int mod) {
        long result = 1;
        while (exp > 0) {
            if ((exp & 1) == 1) result = result * base % mod;
            base = base * base % mod;
            exp >>= 1;
        }
        return result;
    }
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
1
1
10000
2
1 2
5000 5000
3
1 2 3
5000 5000 5000
4
1 2 3 4
5000 5000 5000 5000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import java.util.Scanner;

public class ExpectedPower {
	static long mod = (long)1e9 + 7;

	private static long qpow(long x, long y) {
		long res = 1;
		while(y != 0) {
			if((y & 1) == 1) {
				res = res * x % mod;
			}
			x *= x;
			x %= mod;
			y >>= 1;
		}
		return res;
	}

	private static long inv(long x) {
		return qpow(x, mod - 2);
	}

	private static long mo(long x) {
		return (x % mod + mod) % mod;
	}

	static Scanner sc = new Scanner(System.in);
//	static int[][][][] f = new int[][][][];
	static long inv1e4 = inv(10000);
	public static void main(String[] args) {
		int t = sc.nextInt();
		while(t-- > 0) {
			int n = sc.nextInt();
			long[] A = new long[n + 1];
			long[] P = new long[n + 1];
			for(int i = 1; i <= n; i++) {
				A[i] = sc.nextLong();
			}
			for(int i = 1; i <= n; i++) {
				P[i] = sc.nextLong();
				P[i] = P[i] * inv1e4 % mod; // pi/1e4 = pi * inv(1e4)
			}
			long res = solve(A, P);
			System.out.println(res);
		}
	}

	private static long solve(long[] A, long[] P) {
		int n = A.length - 1;
		long[][] f = new long[2][1024]; // [0] => [1] => [0]...
		f[0][0] = 1;
		for(int i = 1; i <= n; i++) {
			int sel = i & 1;
			for(int j = 0; j < 1024; j++) {
				f[sel][j] = 0;
				f[sel][j] = (f[sel][j] + (f[1 - sel][j] * mo(1 - P[i]) % mod)) % mod;
				f[sel][j] = (f[sel][j] + (f[1 - sel][(int)(j ^ A[i])] * P[i] % mod)) % mod;
			}
		}
		long res = 0;
		for(int j = 0; j < 1024; j++) {
			res += f[n & 1][j] * j * j % mod;
			res %= mod;
		}
		return res;
	}
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
3
1
1023
10000
2
1023 1023
10000 10000
6
1023 1023 1023 1023 1023 1023
10000 10000 10000 10000 10000 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
#include <iostream>
#include <vector>
using namespace std;

const int MOD = 1e9 + 7;
const int MAX_N = 1024;

// 快速幂求模
int modpow(int base, int exp, int mod) {
	int result = 1;
	while (exp > 0) {
		if (exp % 2 == 1) result = (1LL * result * base) % mod;
		base = (1LL * base * base) % mod;
		exp /= 2;
	}
	return result;
}

// 快速沃尔什-哈达玛变换（FWHT）
void fwht(vector<int>& a, bool inverse) {
	int n = a.size();
	for (int len = 1; 2 * len <= n; len <<= 1) {
		for (int i = 0; i < n; i += 2 * len) {
			for (int j = 0; j < len; ++j) {
				int u = a[i + j];
				int v = a[i + j + len];
				a[i + j] = (u + v) % MOD;
				a[i + j + len] = (u - v + MOD) % MOD;
			}
		}
	}
	if (inverse) {
		int inv_n = modpow(n, MOD - 2, MOD);
		for (int i = 0; i < n; ++i)
			a[i] = 1LL * a[i] * inv_n % MOD;
	}
}

int main() {
	int t;
	cin >> t;

	while (t--) {
		int n;
		cin >> n;

		vector<int> a(n);
		vector<int> p(n);
		for (int i = 0; i < n; i++) cin >> a[i];
		for (int i = 0; i < n; i++) cin >> p[i];

		// 初始化概率分布
		vector<int> prob(MAX_N, 0);
		prob[0] = 1;

		for (int i = 0; i < n; i++) {
			// 计算 p_i 和 (1 - p_i)
			int p_i = (1LL * p[i] * modpow(10000, MOD - 2, MOD)) % MOD;
			int p_not_i = (1 - p_i + MOD) % MOD;

			vector<int> v(MAX_N, 0);
			v[0] = p_not_i;
			v[a[i]] = p_i;

			// 对 prob 和 v 进行 FWHT
			fwht(prob, false);
			fwht(v, false);

			// 点乘并取模
			for (int j = 0; j < MAX_N; j++) {
				prob[j] = (1LL * prob[j] * v[j]) % MOD;
			}

			// 逆变换
			fwht(prob, true);
		}

		// 计算期望值
		int result = 0;
		for (int x = 0; x < MAX_N; x++) {
			int val = (1LL * x * x % MOD) * prob[x] % MOD;
			result = (result + val) % MOD;
		}

		cout << result << endl;
	}

	return 0;
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
To generate a challenging test input that exposes the bug in the given buggy code, we need to focus on edge cases and scenarios that can highlight issues in the implementation. Here are the steps to consider:

1. **Edge Cases for Array Lengths**:
   - Test with the minimum and maximum allowed lengths for `n`.
   - Test with a single element array to see if the code handles it correctly.

2. **Edge Cases for Element Values**:
   - Test with the maximum value of `a_i` (1023) and the minimum value (1).
   - Test with all elements being the same to see if the code handles uniform distributions correctly.

3. **Edge Cases for Probabilities**:
   - Test with probabilities of 0 and 10000 to see if the code handles deterministic cases correctly.
   - Test with probabilities close to 0 and 10000 to see if the code handles very small or very large probabilities correctly.

4. **Complex Cases**:
   - Test with a mix of different values and probabilities to ensure the code handles various combinations correctly.

Based on these considerations, here is a small-scale test input that is complete and valid:

```plaintext
4
1
1
10000
2
1023 1
10000 1
2
1 1023
1 10000
3
1 1023 512
5000 5000 5000
```

This test input includes:
- A single element array with a probability of 1.
- An array with the maximum value and a probability of 1.
- An array with the minimum and maximum values with extreme probabilities.
- An array with a mix of values and moderate probabilities.


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
#include<bits/stdc++.h>
using namespace std;
using ll=long long;
ll mod=1e9+7;
ll poww(ll a,ll b){
  ll ret=1;
  while(b){
    if(b&1){
      ret=ret*a%mod;
    }
    a=a*a%mod;
    b>>=1;
  }
  return ret;
}
void solve(){
  ll n;
  cin>>n;
  vector<ll>a(n),p(n);
  for(auto &i:a)cin>>i;
  for(auto &i:p)cin>>i;
  ll inv=poww(1e4,mod-2);
  vector<ll>dp(1024);
  dp[0]=1;
  vector<int>invp(n),notinvp(n);
  for(int i=0;i<n;++i){
    invp[i]=(p[i]*inv)%mod;
    notinvp[i]=(10000-p[i])*inv%mod;
  }
  for(ll j=0;j<n;++j){
    auto ndp=dp;
    for(ll i=0;i<1024;++i){
      ndp[i^a[j]]=(notinvp[j]*dp[i^a[j]]%mod+invp[j]*dp[i]%mod)%mod;
    }
    dp=ndp;
  }
  ll sum=0;
  for(ll i=1;i<1024;++i){
    sum=(sum+i*i*dp[i]%mod)%mod;
  }
  cout<<sum<<"\n";
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout << fixed << setprecision(10);
  int testcases = 1;
  cin >> testcases;
  while(testcases--)solve();
  return 0;
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
1
2
1 1
10000 10000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
from sys import stdin

class FastIO:
    def __init__(self):
        self.random_seed = 0
        self.flush = False
        self.inf = 1 << 32
        self.dire4 = [(0, -1), (0, 1), (1, 0), (-1, 0)]
        self.dire8 = [(0, -1), (0, 1), (1, 0), (-1, 0)] + [(1, -1), (1, 1), (-1, -1), (-1, 1)]
        return

    @staticmethod
    def read_int():
        return int(stdin.readline().rstrip())

    @staticmethod
    def read_float():
        return float(stdin.readline().rstrip())

    @staticmethod
    def read_list_ints():
        return list(map(int, stdin.readline().rstrip().split()))

    @staticmethod
    def read_list_ints_minus_one():
        return list(map(lambda x: int(x) - 1, stdin.readline().rstrip().split()))

    @staticmethod
    def read_str():
        return stdin.readline().rstrip()

    @staticmethod
    def read_list_strs():
        return stdin.readline().rstrip().split()

    def get_random_seed(self):
        import random
        self.random_seed = random.randint(0, 10 ** 9 + 7)
        return

    def st(self, x):
        return print(x, flush=self.flush)

    def yes(self, s=None):
        self.st("Yes" if not s else s)
        return

    def no(self, s=None):
        self.st("No" if not s else s)
        return

    def lst(self, x):
        return print(*x, flush=self.flush)

    def flatten(self, lst):
        self.st("\n".join(str(x) for x in lst))
        return

    @staticmethod
    def max(a, b):
        return a if a > b else b

    @staticmethod
    def min(a, b):
        return a if a < b else b

    @staticmethod
    def ceil(a, b):
        return a // b + int(a % b != 0)

    @staticmethod
    def accumulate(nums):
        n = len(nums)
        pre = [0] * (n + 1)
        for i in range(n):
            pre[i + 1] = pre[i] + nums[i]
        return pre

class Solution:
    def __init__(self):
        return

    @staticmethod
    def main(ac=FastIO()):
        """
        url: https://codeforces.com/contest/2020/problem/E
        tag: observation|linear_dp|data_range|brute_force
        """
        mod = 10 ** 9 + 7
        m = pow(10, -4, mod)
        for _ in range(ac.read_int()):
            ac.read_int()
            nums = ac.read_list_ints()
            p = [x * m % mod for x in ac.read_list_ints()]
            np = [0] * (1 << 10)
            for i, num in enumerate(nums):
                np[num] = p[i] * (1 - np[num]) + (1 - p[i]) * np[num]
                np[num] %= mod
            dp = [0] * (1 << 10)
            dp[0] = 1
            ndp = [0] * (1 << 10)

            for i in range(1 << 10):
                if np[i]:

                    for x in range(1 << 10):
                        ndp[x] = dp[x] * (1 - np[i]) + dp[x ^ i] * np[i]
                    dp = ndp[:]
            res = 0
            for num in range(1 << 10):
                res += dp[num] * num * num
                res %= mod
            ac.st(res)
        return

Solution().main()

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
1
1
10000
2
1 2
5000 5000
3
1 2 3
3333 6666 10000
6
1 2 3 4 5 6
1234 5678 9101 1111 2222 3333
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import sys
import collections
import math
import bisect
import heapq
#import itertools
import functools
import copy
input = sys.stdin.readline

def solve():
    M = 10 ** 9 + 7
    n = int(input())
    a = list(map(int, input().split()))
    p = list(map(int, input().split()))

    dp = [0] * 1024
    dp[0] = 1
    temp = [0] * 1024
    for i in range(n):
        ai, pi = a[i], p[i]
        ni = 10000 - pi
        for j in range(1024):
            temp[j] = ni * dp[j] % M
        for j in range(1024):
            temp[j ^ ai] += pi * dp[j]
            temp[j ^ ai] %= M
        dp, temp = temp, dp
    den = pow(10000, -n, M)
    res = 0
    for i in range(1024):
        res += i * i * dp[i] * den
        res %= M
    print(res)
    return

t = int(input())
for _ in range(t):
    solve()

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
4
1
1
5000
2
1 1
5000 5000
3
1 1 1
1000 2000 3000
4
1 1 1 1
1000 2000 3000 4000
```


**Task:**
Generate a challenging test input that exposes the bug in the buggy code of the algorithm problem:
Algorithm Problem:
Title: Expected Power
time_limit_ms: 4000
memory_limit_mb: 256
Description: You are given an array of $n$ integers $a_1,a_2,\ldots,a_n$. You are also given an array $p_1, p_2, \ldots, p_n$.

Let $S$ denote the random multiset (i. e., it may contain equal elements) constructed as follows:

  * Initially, $S$ is empty.    * For each $i$ from $1$ to $n$, insert $a_i$ into $S$ with probability $\frac{p_i}{10^4}$. Note that each element is inserted independently.

Denote $f(S)$ as the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all elements of $S$. Please calculate the expected value of $(f(S))^2$. Output the answer modulo $10^9 + 7$.

Formally, let $M = 10^9 + 7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q \not \equiv 0 \pmod{M}$. Output the integer equal to $p \cdot q^{-1} \bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod{M}$.

Input: Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$).

The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 1023$).

The third line of each test case contains $n$ integers $p_1,p_2,\ldots,p_n$ ($1 \le p_i \le 10^4$).

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output: For each test case, output the expected value of $(f(S))^2$, modulo $10^9 + 7$.

Examples:
input:
4
2
1 2
5000 5000
2
1 1
1000 2000
6
343 624 675 451 902 820
6536 5326 7648 2165 9430 5428
1
1
10000
output:
500000007
820000006
280120536
1

Note: In the first test case, $a = [1, 2]$ and each element is inserted into $S$ with probability $\frac{1}{2}$, since $p_1 = p_2 = 5000$ and $\frac{p_i}{10^4} = \frac{1}{2}$. Thus, there are $4$ outcomes for $S$, each happening with the same probability of $\frac{1}{4}$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$.    * $S = \\{2\\}$. In this case, $f(S) = 2$, $(f(S))^2 = 4$.    * $S = \\{1,2\\}$. In this case, $f(S) = 1 \oplus 2 = 3$, $(f(S))^2 = 9$.

Hence, the answer is $0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{4} + 4\cdot \frac{1}{4} + 9 \cdot \frac{1}{4} = \frac{14}{4} = \frac{7}{2} \equiv 500\,000\,007 \pmod{10^9 + 7}$.

In the second test case, $a = [1, 1]$, $a_1$ is inserted into $S$ with probability $0.1$, while $a_2$ is inserted into $S$ with probability $0.2$. There are $3$ outcomes for $S$:

  * $S = \varnothing$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $(1-0.1) \cdot (1-0.2) = 0.72$.    * $S = \\{1\\}$. In this case, $f(S) = 1$, $(f(S))^2 = 1$. This happens with probability $(1-0.1) \cdot 0.2 + 0.1 \cdot (1-0.2) = 0.26$.    * $S = \\{1, 1\\}$. In this case, $f(S) = 0$, $(f(S))^2 = 0$. This happens with probability $0.1 \cdot 0.2 = 0.02$.

Hence, the answer is $0 \cdot 0.72 + 1 \cdot 0.26 + 0 \cdot 0.02 = 0.26 = \frac{26}{100} \equiv 820\,000\,006 \pmod{10^9 + 7}$.

Buggy Code:
import java.util.*;

public class Main {
    static final int MOD = 1_000_000_007;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int t = sc.nextInt();
        while(t-- > 0) {
        // Input size of array
        int n = sc.nextInt();

        // Input arrays
        int[] a = new int[n];
        int[] p = new int[n];
        for (int i = 0; i < n; i++) a[i] = sc.nextInt();
        for (int i = 0; i < n; i++) p[i] = sc.nextInt();

        // Solve the problem
        System.out.println(calculateExpectedXORSquared(n, a, p));
    }
    }

    static long calculateExpectedXORSquared(int n, int[] a, int[] p) {
        // Determine the maximum XOR value dynamically
        int maxElement = 0;
        for (int num : a) {
            maxElement = Math.max(maxElement, num);
        }
        int MAX_XOR = 1;
        while (MAX_XOR <= maxElement) {
            MAX_XOR *= 2;
        }

        // Probability array (converted to modular arithmetic)
        long[] prob = new long[n];
        for (int i = 0; i < n; i++) {
            prob[i] = (p[i] * modInverse(10_000, MOD)) % MOD;
        }

        // DP array
        long[][] dp = new long[2][MAX_XOR];
        dp[0][0] = 1; // Base case: probability of XOR=0 with no elements is 1.

        // Fill DP table
        for (int i = 1; i <= n; i++) {
            for (int x = 0; x < MAX_XOR; x++) {
                dp[i % 2][x] = (dp[(i - 1) % 2][x] * (MOD + 1 - prob[i - 1]) % MOD
                               + dp[(i - 1) % 2][x ^ a[i - 1]] * prob[i - 1]) % MOD;
            }
        }

        // Compute expected value of (f(S))^2
        long result = 0;
        for (int x = 0; x < MAX_XOR; x++) {
            long probX = dp[n % 2][x];
            result = (result + probX * x % MOD * x % MOD) % MOD;
        }

        return result;
    }

    // Modular inverse using Fermat's Little Theorem
    static long modInverse(long a, int m) {
        return modPower(a, m - 2, m);
    }

    // Modular exponentiation
    static long modPower(long base, long exp, int mod) {
        long result = 1;
        while (exp > 0) {
            if ((exp & 1) == 1) result = result * base % mod;
            base = base * base % mod;
            exp >>= 1;
        }
        return result;
    }
}

**Instructions:**
- Focus on edge cases or scenarios that maximize the failure probability in faulty solutions.
- Due to the output length limit, you should generate a **small-scale** test input that is **complete and valid**.
- Output the test input directly, not code to generate it.

**Output format:**
```plaintext
{test input}
```

Think step by step.

Response:
```plaintext
1
3
1 2 3
10000 10000 10000
```