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.
from os import path
import sys, time
# mod = int(1e9 + 7)
# import re
from math import ceil, floor, gcd, log, log2, factorial, sqrt
from collections import defaultdict, Counter, OrderedDict, deque
from itertools import combinations, accumulate
# from string import ascii_lowercase ,ascii_uppercase
from bisect import *
from functools import reduce
from operator import mul

star = lambda x: print(' '.join(map(str, x)))
grid = lambda r: [lint() for i in range(r)]
INF = float('inf')
if (path.exists('input.txt')):
    sys.stdin = open('input.txt', 'r')
    sys.stdout = open('output.txt', 'w')
import sys
from sys import stdin, stdout
from collections import *
from math import gcd, floor, ceil


def st():
    return list(stdin.readline().strip())


def inp():
    return int(stdin.readline())


def inlt():
    return list(map(int, stdin.readline().split()))


def invr():
    return map(int, stdin.readline().split())





def solve():
    n,m = invr()
    ans = float("inf")
    res = 0
    for i in range(31,-1,-1):
        if (n & pow(2,i)) and not(m & pow(2,i)):
            print(min(ans,res))
            return
        elif (m & pow(2,i)) and not(n & pow(2,i)):
            res += pow(2,i)
        elif not(n & pow(2,i)) and not(m & pow(2,i)):
            ans = min(ans,pow(2,i)+res)
    print(ans)
    return

t = 1
t = inp()
for _ in range(t):
    solve()
