{"trustable":true,"prependHtml":"\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\" type\u003d\"text/javascript\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003eThere is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can\u0027t move on red tiles, he can move only on black tiles.\u003cbr\u003e\u003cbr\u003eWrite a program to count the number of black tiles which he can reach by repeating the moves described above. \u003cbr\u003e\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20.\u003cbr\u003e\u003cbr\u003eThere are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.\u003cbr\u003e\u003cbr\u003e\u0027.\u0027 - a black tile \u003cbr\u003e\u0027#\u0027 - a red tile \u003cbr\u003e\u0027@\u0027 - a man on a black tile(appears exactly once in a data set) \u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself). \u003cbr\u003e"}},{"title":"Sample","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e6 9\r\n....#.\r\n.....#\r\n......\r\n......\r\n......\r\n......\r\n......\r\n#@...#\r\n.#..#.\r\n11 9\r\n.#.........\r\n.#.#######.\r\n.#.#.....#.\r\n.#.#.###.#.\r\n.#.#..@#.#.\r\n.#.#####.#.\r\n.#.......#.\r\n.#########.\r\n...........\r\n11 6\r\n..#..#..#..\r\n..#..#..#..\r\n..#..#..###\r\n..#..#..#@.\r\n..#..#..#..\r\n..#..#..#..\r\n7 7\r\n..#.#..\r\n..#.#..\r\n###.###\r\n...@...\r\n###.###\r\n..#.#..\r\n..#.#..\r\n0 0\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e45\r\n59\r\n6\r\n13\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}