{"problem":{"name":"Reverse and Compare","description":{"content":"You have a string $A = A_1 A_2 ... A_n$ consisting of lowercase English letters. You can choose any two indices $i$ and $j$ such that $1 \\leq i \\leq j \\leq n$ and reverse substring $A_i A_{i+1} ... A_","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"agc019_b"},"statements":[{"statement_type":"Markdown","content":"You have a string $A = A_1 A_2 ... A_n$ consisting of lowercase English letters.\nYou can choose any two indices $i$ and $j$ such that $1 \\leq i \\leq j \\leq n$ and reverse substring $A_i A_{i+1} ... A_j$.\nYou can perform this operation at most once.\nHow many different strings can you obtain?\n\n## Constraints\n\n*   $1 \\leq |A| \\leq 200,000$\n*   $A$ consists of lowercase English letters.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$A$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"agc019_b","tags":[],"sample_group":[["aatt","5\n\nYou can obtain `aatt` (don't do anything), `atat` (reverse $A[2..3]$), `atta` (reverse $A[2..4]$), `ttaa` (reverse $A[1..4]$) and `taat` (reverse $A[1..3]$)."],["xxxxxxxxxx","1\n\nWhatever substring you reverse, you'll always get `xxxxxxxxxx`."],["abracadabra","44"]],"created_at":"2026-03-03 11:01:13"}}