You are given two integers n and m. Find the \operatorname{MEX} of the sequence n ⊕ 0, n ⊕ 1, …, n ⊕ m. Here, ⊕ is the [bitwise XOR operator](https://en.wikipedia.org/wiki/Bitwise_operation#XOR).

\operatorname{MEX} of the sequence of non-negative integers is the smallest non-negative integer that doesn't appear in this sequence. For example, \operatorname{MEX}(0, 1, 2, 4) = 3, and \operatorname{MEX}(1, 2021) = 0. 

Input

The first line contains a single integer t (1 ≤ t ≤ 30 000) — the number of test cases.

The first and only line of each test case contains two integers n and m (0 ≤ n, m ≤ 10^9).

Output

For each test case, print a single integer — the answer to the problem.

Example

Input


5
3 5
4 6
3 2
69 696
123456 654321


Output


4
3
0
640
530866

Note

In the first test case, the sequence is 3 ⊕ 0, 3 ⊕ 1, 3 ⊕ 2, 3 ⊕ 3, 3 ⊕ 4, 3 ⊕ 5, or 3, 2, 1, 0, 7, 6. The smallest non-negative integer which isn't present in the sequence i. e. the \operatorname{MEX} of the sequence is 4.

In the second test case, the sequence is 4 ⊕ 0, 4 ⊕ 1, 4 ⊕ 2, 4 ⊕ 3, 4 ⊕ 4, 4 ⊕ 5, 4 ⊕ 6, or 4, 5, 6, 7, 0, 1, 2. The smallest non-negative integer which isn't present in the sequence i. e. the \operatorname{MEX} of the sequence is 3.

In the third test case, the sequence is 3 ⊕ 0, 3 ⊕ 1, 3 ⊕ 2, or 3, 2, 1. The smallest non-negative integer which isn't present in the sequence i. e. the \operatorname{MEX} of the sequence is 0.
import sys
from math import *
import builtins
import string
import bisect

alphabets = list(string.ascii_lowercase)
ALPHABETS = list(string.ascii_uppercase)

# # For getting input from input.txt file
# sys.stdin = open('input.txt', 'r')
#
# # Printing the Output to output.txt file
# sys.stdout = open('output.txt', 'w')

# input = sys.stdin.readline


def print(x, end='\n'):
    sys.stdout.write(str(x) + end)


# IO helpers
def get_int():
    return int(input())


def get_list_ints():
    return list(map(int, input().split()))


def get_char_list():
    s = input()
    return list(s[:len(s)])


def get_tuple_ints():
    return tuple(map(int, input().split()))


def print_iterable(p):
    print(" ".join(map(str, p)))


def floorSearch(arr, low, high, x):
    if low > high:
        return -1
    if x >= arr[high]:
        return high
    mid = int((low + high) / 2)
    if arr[mid] == x:
        return mid
    if mid > 0 and arr[mid - 1] <= x < arr[mid]:
        return mid - 1
    if x < arr[mid]:
        return floorSearch(arr, low, mid - 1, x)
    return floorSearch(arr, mid + 1, high, x)


def binary_search(arr, x):
    low = 0
    high = len(arr) - 1
    mid = 0
    while low <= high:
        mid = (high + low) // 2
        if arr[mid] < x:
            low = mid + 1
        elif arr[mid] > x:
            high = mid - 1
        else:
            return mid
    return high


def main():
    p = get_int()
    for q in range(p):
        n, m = get_list_ints()
        ans = 0
        m += 1
        for k in range(30, -1, -1):
            if n >= m:
                break
            if (n >> k & 1) == (m >> k & 1):
                pass
            elif (m >> k & 1) == 1:
                ans |= 1 << k
                n |= 1 << k
                m |= 1 << k
        print(ans)
    pass


if __name__ == '__main__':
    main()
