6702：^&^

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 \leq A, B < 2 ^ {32} $)

For each test case,you should output the answer and a line for each answer.