Given two integers S and F, what is the XOR (exclusive-or) of all numbers between S and F (inclusive)?

The first line of input is the integer T, which is the number of test cases (1 ≤ T ≤ 1000). T lines follow, with each line containing two integers S and F (1 ≤ S ≤ F ≤ 1 000 000 000).

For each test case, output the (decimal) value of the XOR of all numbers between S and F, inclusive.