{"problem":{"name":"ATCoder","description":{"content":"You are given a string $S$ consisting of uppercase English letters. Find the length of the longest _ACGT string_ that is a substring (see Notes) of $S$. Here, a ACGT string is a string that contains n","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc122_b"},"statements":[{"statement_type":"Markdown","content":"You are given a string $S$ consisting of uppercase English letters. Find the length of the longest _ACGT string_ that is a substring (see Notes) of $S$.\nHere, a ACGT string is a string that contains no characters other than `A`, `C`, `G` and `T`.\n\n## Constraints\n\n*   $S$ is a string of length between $1$ and $10$ (inclusive).\n*   Each character in $S$ is an uppercase English letter.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$S$\n\n[samples]\n\n## Notes\n\nA substring of a string $T$ is a string obtained by removing zero or more characters from the beginning and the end of $T$.\nFor example, the substrings of `ATCODER` include `TCO`, `AT`, `CODER`, `ATCODER` and (the empty string), but not `AC`.","is_translate":false,"language":"English"}],"meta":{"iden":"abc122_b","tags":[],"sample_group":[["ATCODER","3\n\nAmong the ACGT strings that are substrings of `ATCODER`, the longest one is `ATC`."],["HATAGAYA","5\n\nAmong the ACGT strings that are substrings of `HATAGAYA`, the longest one is `ATAGA`."],["SHINJUKU","0\n\nAmong the ACGT strings that are substrings of `SHINJUKU`, the longest one is (the empty string)."]],"created_at":"2026-03-03 11:01:14"}}