{"problem":{"name":"kasaka","description":{"content":"Given is a string $S$ consisting of lowercase English letters. Determine whether adding some number of `a`'s (possibly zero) at the beginning of $S$ can make it a palindrome. Here, a string of length ","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc237_c"},"statements":[{"statement_type":"Markdown","content":"Given is a string $S$ consisting of lowercase English letters. Determine whether adding some number of `a`'s (possibly zero) at the beginning of $S$ can make it a palindrome.\nHere, a string of length $N$, $A=A_1A_2\\ldots A_N$, is said to be a palindrome when $A_i=A_{N+1-i}$ for every $1\\leq i\\leq N$.\n\n## Constraints\n\n*   $1 \\leq \\lvert S \\rvert \\leq 10^6$\n*   $S$ consists of lowercase English letters.\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":"abc237_c","tags":[],"sample_group":[["kasaka","Yes\n\nBy adding one `a` at the beginning of `kasaka`, we have `akasaka`, which is a palindrome, so `Yes` should be printed."],["atcoder","No\n\nAdding any number of `a`'s at the beginning of `atcoder` does not make it a palindrome."],["php","Yes\n\n`php` itself is a palindrome. Adding zero `a`'s at the beginning of $S$ is allowed, so `Yes` should be printed."]],"created_at":"2026-03-03 11:01:13"}}