Little Sergey
Little Sergey has bought a little nuclear reactor. He decided to set up a password for it. But he has forgotten the password. Little Sergey remembers that the password was equal to xor (exclusive or) of all numbers from interval [ L; R ] inclusive. Help him to remind password.
Input The first line of input contains two integers L and R (1<=L<=R<=10000000000000066).
OutputOutput one integer - the answer to the problem.
Input:
Output:
2 8Output:
9Submit solution
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