{"problem":{"name":"String Invasion","description":{"content":"Given is a string $S$ of length $N$. Let $s_i$ denote the $i$\\-th character of $S$. Find the maximum number of times the following operation can be done. *   Choose three consecutive characters in $S","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"arc113_c"},"statements":[{"statement_type":"Markdown","content":"Given is a string $S$ of length $N$. Let $s_i$ denote the $i$\\-th character of $S$. Find the maximum number of times the following operation can be done.\n\n*   Choose three consecutive characters in $S$, $s_i,s_{i+1},s_{i+2}\\quad (1\\leq i\\leq |S|-2)$, such that $s_i=s_{i+1}\\neq s_{i+2}$, and replace $s_{i+2}$ with $s_i$.\n\n## Constraints\n\n*   $3 \\leq |S| \\leq 2\\times 10^5$\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":"arc113_c","tags":[],"sample_group":[["accept","3\n\nWe can do the operation three times, as follows:\n\n*   do it with $i=2$, changing the string to `acccpt`;\n*   do it with $i=3$, changing the string to `acccct`;\n*   do it with $i=4$, changing the string to `accccc`."],["atcoder","0"],["anerroroccurred","16"]],"created_at":"2026-03-03 11:01:14"}}