{"problem":{"name":"XOR Replace","description":{"content":"There is a sequence of length $N$: $a = (a_1, a_2, ..., a_N)$. Here, each $a_i$ is a non-negative integer. Snuke can repeatedly perform the following operation: *   Let the XOR of all the elements in","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"agc016_d"},"statements":[{"statement_type":"Markdown","content":"There is a sequence of length $N$: $a = (a_1, a_2, ..., a_N)$. Here, each $a_i$ is a non-negative integer.\nSnuke can repeatedly perform the following operation:\n\n*   Let the XOR of all the elements in $a$ be $x$. Select an integer $i$ ($1 ≤ i ≤ N$) and replace $a_i$ with $x$.\n\nSnuke's objective is to match $a$ with another sequence $b = (b_1, b_2, ..., b_N)$. Here, each $b_i$ is a non-negative integer.\nDetermine whether the objective is achievable, and find the minimum necessary number of operations if the answer is positive.\n\n## Constraints\n\n*   $2 ≤ N ≤ 10^5$\n*   $a_i$ and $b_i$ are integers.\n*   $0 ≤ a_i, b_i < 2^{30}$\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n$a_1$ $a_2$ $...$ $a_N$\n$b_1$ $b_2$ $...$ $b_N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"agc016_d","tags":[],"sample_group":[["3\n0 1 2\n3 1 0","2\n\nAt first, the XOR of all the elements of $a$ is $3$. If we replace $a_1$ with $3$, $a$ becomes $(3, 1, 2)$.\nNow, the XOR of all the elements of $a$ is $0$. If we replace $a_3$ with $0$, $a$ becomes $(3, 1, 0)$, which matches $b$."],["3\n0 1 2\n0 1 2","0"],["2\n1 1\n0 0","\\-1"],["4\n0 1 2 3\n1 0 3 2","5"]],"created_at":"2026-03-03 11:01:13"}}