B"You are given two integers n and m . Find the operatorname{MEX} of the sequence n oplus 0, n oplus 1, ldots, n oplus m . Here, oplus is the bitwise XOR operator. 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 . 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 ). For each test case, print a single integer -- the answer to the problem. In the first test case, the sequence is 3 oplus 0, 3 oplus 1, 3 oplus 2, 3 oplus 3, 3 oplus 4, 3 oplus 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 oplus 0, 4 oplus 1, 4 oplus 2, 4 oplus 3, 4 oplus 4, 4 oplus 5, 4 oplus 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 oplus 0, 3 oplus 1, 3 oplus 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 . "...