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
import math
from math import *
import builtins
import collections
import bisect
import os
from io import BytesIO, IOBase


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) - 1])


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


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

def CountFrequency(arr):
    return collections.Counter(arr) 
 
def reverse(s):
    l=len(s)
    for i in range(l//2):
        s[i],s[l-i-1]=s[l-i-1],s[i]
    return s


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

#STD lower bound equivalent in python
def lower_bound(arr,x):
    return bisect.bisect_left(arr, x, lo=0, hi=len(arr))
 
 #STD upper bound equivalent in python
def upper_bound(arr,x):
    return bisect.bisect_right(arr, x, lo=0, hi=len(arr))


def pow(a,n):
    if n==0:
        return 1
    elif n%2==0:
        return ((pow(a,n//2)%const)*(pow(a,n//2)%const))%const
    else:
        return ((pow(a,n//2)%const)*(pow(a,n//2)%const)*(a%const))%const

def operate(v,w):
    ans=0
    if v>=w:
        return 0
    else:
        for i in range(31, -1, -1):
            k = v >> i;
            l = w >> i;
            if v>=w:
                break
            if (k & 1)==1 and (l & 1)==1:
                continue
            elif (k & 1)==0 and (l & 1)==0:
                continue
            elif (l & 1)==1:
                ans |= 1 << i
                v |= 1 << i
        return ans
def main(): 
    n=get_int()
    for i in range(n):
        [n,m]=get_list_ints()
        print(operate(n,m+1))
    pass


##Fast Input Output

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, 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()