{"problem":{"name":"Stones","description":{"content":"There are $N$ stones arranged in a row. Every stone is painted white or black. A string $S$ represents the color of the stones. The $i$\\-th stone from the left is white if the $i$\\-th character of $S$","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"tenka1_2019_c"},"statements":[{"statement_type":"Markdown","content":"There are $N$ stones arranged in a row. Every stone is painted white or black. A string $S$ represents the color of the stones. The $i$\\-th stone from the left is white if the $i$\\-th character of $S$ is `.`, and the stone is black if the character is `#`.\nTakahashi wants to change the colors of some stones to black or white so that there will be no white stone immediately to the right of a black stone. Find the minimum number of stones that needs to be recolored.\n\n## Constraints\n\n*   $1 \\leq N \\leq 2\\times 10^5$\n*   $S$ is a string of length $N$ consisting of `.` and `#`.\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":"tenka1_2019_c","tags":[],"sample_group":[["3\n#.#","1\n\nIt is enough to change the color of the first stone to white."],["5\n#.##.","2"],["9\n.........","0"]],"created_at":"2026-03-03 11:01:14"}}