^&^

Bit operation is a common computing method in computer science ,Now we have two positive integers A and B ,Please find a positive integer C that minimize the value of the formula (A xor C) & (B xor C) .Sometimes we can find a lot of C to do this ,So you need to find the smallest C that meets the criteria .

For example ,Let's say A is equal to 5 and B is equal to 3 ,we can choose C=1,3.... ,so the answer we're looking for C is equal to 1.

If the value of the expression is 0 when C=0, please print 1.

The input file contains T test samples.(1<=T<=100)

The first line of input file is an integer T.

Then the T lines contains 2 positive integers, A and B, ( 1 <= A, B < 2^32 )

1
3 5

1