{"raw_statement":[{"iden":"problem statement","content":"Let $f(A, B)$ be the exclusive OR of $A, A+1, ..., B$. Find $f(A, B)$.\n\nWhat is exclusive OR?\n\nThe bitwise exclusive OR of integers $c_1, c_2, ..., c_n$ (let us call it $y$) is defined as follows:\n\n*   When $y$ is written in base two, the digit in the $2^k$'s place ($k \\geq 0$) is $1$ if, the number of integers among $c_1, c_2, ...c_m$ whose binary representations have $1$ in the $2^k$'s place, is odd, and $0$ if that count is even.\n\nFor example, the exclusive OR of $3$ and $5$ is $6$. (When written in base two: the exclusive OR of `011` and `101` is `110`.)"},{"iden":"constraints","content":"*   All values in input are integers.\n*   $0 \\leq A \\leq B \\leq 10^{12}$"},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$A$ $B$"},{"iden":"sample input 1","content":"2 4"},{"iden":"sample output 1","content":"5\n\n$2, 3, 4$ are `010`, `011`, `100` in base two, respectively. The exclusive OR of these is `101`, which is $5$ in base ten."},{"iden":"sample input 2","content":"123 456"},{"iden":"sample output 2","content":"435"},{"iden":"sample input 3","content":"123456789012 123456789012"},{"iden":"sample output 3","content":"123456789012"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}