{"problem":{"name":"Strivore","description":{"content":"How many strings can be obtained by applying the following operation on a string $S$ exactly $K$ times: \"choose one lowercase English letter and insert it somewhere\"? The answer can be enormous, so pr","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc171_f"},"statements":[{"statement_type":"Markdown","content":"How many strings can be obtained by applying the following operation on a string $S$ exactly $K$ times: \"choose one lowercase English letter and insert it somewhere\"?\nThe answer can be enormous, so print it modulo $(10^9+7)$.\n\n## Constraints\n\n*   $K$ is an integer between $1$ and $10^6$ (inclusive).\n*   $S$ is a string of length between $1$ and $10^6$ (inclusive) consisting of lowercase English letters.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$K$\n$S$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc171_f","tags":[],"sample_group":[["5\noof","575111451\n\nFor example, we can obtain `proofend`, `moonwolf`, and `onionpuf`, while we cannot obtain `oofsix`, `oofelevennn`, `voxafolt`, or `fooooooo`."],["37564\nwhydidyoudesertme","318008117"]],"created_at":"2026-03-03 11:01:14"}}