Problems
XOR sum
XOR sum
Find the \textbf{XOR} of all the numbers on a segment $[l, r]$.
\InputFile
Two integers $l$ and $r~(0 \le l \le r \le 10^{18})$.
\OutputFile
Print the \textbf{XOR} of all the numbers on a segment $[l, r]$.
Input example #1
3 8
Output example #1
11