{"raw_statement":[{"iden":"problem statement","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."},{"iden":"constraints","content":"*   $1 \\leq N \\leq 2\\times 10^5$\n*   $S$ is a string of length $N$ consisting of `.` and `#`."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$\n$S$"},{"iden":"sample input 1","content":"3\n#.#"},{"iden":"sample output 1","content":"1\n\nIt is enough to change the color of the first stone to white."},{"iden":"sample input 2","content":"5\n#.##."},{"iden":"sample output 2","content":"2"},{"iden":"sample input 3","content":"9\n........."},{"iden":"sample output 3","content":"0"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}