human
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.
 Can you provide a Python code to find the \operatorname{MEX} of the sequence n ⊕ 0, n ⊕ 1, …, n ⊕ m?
assistant
#Here is Python code to find the \operatorname{MEX} of the sequence n ⊕ 0, n ⊕ 1, …, n ⊕ m.

import sys

# file = open("error.txt", "r+")
# file.truncate(0)
# file.close()

# def debug(*args):
#     import sys
#     if __debug__:
#         orig_stdout = sys.stdout
#         f = open('error.txt', 'a')
#         sys.stdout = f
#         for out in args:
#             if isinstance(out, list) and all(isinstance(elem, list) for elem in out):
#                 [[print(' '.join(list(map(str,s))))]for s in out]
#             else:
#                 sys.stdout.write(str(out)+' ')
#         print()
#         sys.stdout = orig_stdout
#         f.close()

t=int(input())
for _ in range(t):
    n,m=list(map(int,sys.stdin.readline().strip().split()))
    if  n>m:
        print(0)
    else:
        bin_n=list(map(int,bin(n)[:1:-1]))
        bin_m=list(map(int,bin(m)[:1:-1]))
        # debug(bin_n)
        bin_m.append(0)
        changeable=[]
        min_diff=m-n
        diff_now=0
        for pos in range(len(bin_m)):
            if pos<len(bin_n) and bin_n[pos]==0:
                changeable.append(2**pos)
                diff_now+=changeable[-1]
            elif pos>=len(bin_n):
                changeable.append(2**pos)
                diff_now+=changeable[-1]
            if diff_now>min_diff:
                break
        # debug(changeable,diff_now)
        for c in changeable[::-1]:
            if diff_now-c>min_diff:
                diff_now-=c
        print(diff_now)