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 collections import deque
import heapq
from math import sqrt
import operator
from operator import itemgetter
import sys

import copy

 
inf_var = 0
if inf_var == 1:
    inf = open('input.txt', 'r')
else:
    inf = sys.stdin
 
input = inf.readline
# sys.stdout = open('output.txt', 'w')
 
def read_one_int():
    return int(input().rstrip('\n'))


def read_one_float():
    return float(input().rstrip('\n'))
 
 
def read_list_of_ints():
    res = [int(val) for val in (input().rstrip('\n')).split(' ')]
    return res
 
def read_str():
    return input().rstrip()


def main():
    tests = read_one_int()

    for _ in range(tests):
        n, m = read_list_of_ints()

        if m < n:
            print(0)
            continue

        if m == 0:
            print(n ^ (m + 1))
            continue

        n_bin = [0] * 30
        m_bin = [0] * 30

        bit = 1
        for i in range(30):
            if n & bit:
                n_bin[i] = 1
            elif bit <= n:
                n_bin[i] = 0

            if m & bit:
                m_bin[i] = 1
            elif bit <= m:
                m_bin[i] = 0

            bit <<= 1

        last_m_bit = None
        for i in range(len(m_bin) - 1, -1, -1):
            if m_bin[i] == 1:
                last_m_bit = i
                break

        bits_to_change = []
        can_decrease = False
        for i in range(last_m_bit - 1, -1, -1):
            if not can_decrease:
                if m_bin[i]:
                    continue
                elif n_bin[i]:
                    bits_to_change.append(i)
                    can_decrease = True
            else:
                if m_bin[i] ^ n_bin[i]:
                    bits_to_change.append(i)

        
        if not bits_to_change:
            last_to_change = None
            for i in range(len(m_bin)):
                if not m_bin[i] and not n_bin[i]:
                    bits_to_change.append(i)
                    last_to_change = i
                    break

            for i in range(last_to_change - 1, -1, -1):
                if m_bin[i] ^ n_bin[i]:
                    bits_to_change.append(i)

        for bit_n in bits_to_change:
            val = 1 << bit_n
            m ^= val

        res = m ^ n

        print(res)


if __name__== '__main__':
    main()
