{"problem":{"name":"Less than 3","description":{"content":"You are given strings $s$ and $t$, both of length $N$. $s$ and $t$ consist of `0` and `1`. Additionally, in these strings, the same character never occurs three or more times in a row. You can modify ","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"agc030_e"},"statements":[{"statement_type":"Markdown","content":"You are given strings $s$ and $t$, both of length $N$. $s$ and $t$ consist of `0` and `1`. Additionally, in these strings, the same character never occurs three or more times in a row.\nYou can modify $s$ by repeatedly performing the following operation:\n\n*   Choose an index $i$ ($1 \\leq i \\leq N$) freely and invert the $i$\\-th character in $s$ (that is, replace `0` with `1`, and `1` with `0`), under the condition that the same character would not occur three or more times in a row in $s$ after the operation.\n\nYour objective is to make $s$ equal to $t$. Find the minimum number of operations required.\n\n## Constraints\n\n*   $1 \\leq N \\leq 5000$\n*   The lengths of $s$ and $t$ are both $N$.\n*   $s$ and $t$ consists of `0` and `1`.\n*   In $s$ and $t$, the same character never occurs three or more times in a row.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n$s$\n$t$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"agc030_e","tags":[],"sample_group":[["4\n0011\n0101","4\n\nOne possible solution is `0011` → `1011` → `1001` → `1101` → `0101`."],["1\n0\n0","0"],["8\n00110011\n10101010","10"]],"created_at":"2026-03-03 11:01:14"}}