{"problem":{"name":"Wide Flip","description":{"content":"You are given a string $S$ consisting of `0` and `1`. Find the maximum integer $K$ not greater than $|S|$ such that we can turn all the characters of $S$ into `0` by repeating the following operation ","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"arc088_b"},"statements":[{"statement_type":"Markdown","content":"You are given a string $S$ consisting of `0` and `1`. Find the maximum integer $K$ not greater than $|S|$ such that we can turn all the characters of $S$ into `0` by repeating the following operation some number of times.\n\n*   Choose a contiguous segment $[l,r]$ in $S$ whose length is at least $K$ (that is, $r-l+1\\geq K$ must be satisfied). For each integer $i$ such that $l\\leq i\\leq r$, do the following: if $S_i$ is `0`, replace it with `1`; if $S_i$ is `1`, replace it with `0`.\n\n## Constraints\n\n*   $1\\leq |S|\\leq 10^5$\n*   $S_i(1\\leq i\\leq N)$ is either `0` or `1`.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$S$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"arc088_b","tags":[],"sample_group":[["010","2\n\nWe can turn all the characters of $S$ into `0` by the following operations:\n\n*   Perform the operation on the segment $S[1,3]$ with length $3$. $S$ is now `101`.\n*   Perform the operation on the segment $S[1,2]$ with length $2$. $S$ is now `011`.\n*   Perform the operation on the segment $S[2,3]$ with length $2$. $S$ is now `000`."],["100000000","8"],["00001111","4"]],"created_at":"2026-03-03 11:01:13"}}