{"problem":{"name":"Echo","description":{"content":"Given are a positive integer $N$ and a string $S$ of length $N$ consisting of lowercase English letters. Determine whether the string is a concatenation of two copies of some string. That is, determin","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc145_b"},"statements":[{"statement_type":"Markdown","content":"Given are a positive integer $N$ and a string $S$ of length $N$ consisting of lowercase English letters.\nDetermine whether the string is a concatenation of two copies of some string. That is, determine whether there is a string $T$ such that $S = T + T$.\n\n## Constraints\n\n*   $1 \\leq N \\leq 100$\n*   $S$ consists of lowercase English letters.\n*   $|S| = N$\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n$S$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc145_b","tags":[],"sample_group":[["6\nabcabc","Yes\n\nLet $T = $ `abc`, and $S = T + T$."],["6\nabcadc","No"],["1\nz","No"]],"created_at":"2026-03-03 11:01:14"}}