{"trustable":false,"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":"\u003cscript type\u003d\u0027text/x-mathjax-config\u0027\u003eMathJax.Hub.Config({tex2jax: { inlineMath: [[\u0027$\u0027,\u0027$\u0027]] } }); \u003c/script\u003e\n\u003cscript type\u003d\u0027text/javascript\u0027 src\u003d\u0027https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\u0027\u003e\u003c/script\u003e\n\u003cscript type\u003d\u0027text/javascript\u0027\u003esetTimeout(function(){MathJax.Hub.Queue([\u0027Typeset\u0027, MathJax.Hub, \u0027left_view\u0027]);}, 2000);\u003c/script\u003e\n\u003cdiv class\u003d\"panel_content\"\u003e\n\u003cp\u003ewbx梦见一片充满宝藏的沙滩, 它是由若干正方形的块状土地组成的一个W*H矩形区域。wbx决定挖出这片沙滩所有的宝藏,成为传说中的宝藏男孩。不幸的是,在他挖第二块地时就触发了埋藏其中的地雷,他直接被从宿舍的床上炸醒。他恍然大悟,原来这片沙滩上的每一块地,除了宝藏,还有可能是地雷! \u003c/p\u003e\n\u003cp\u003e故事没有就这样结束. 第二天,他又做了相同的梦...\u003c/p\u003e\n \u003cbr\u003e \n \u003cbr\u003e编写一个程序,计算出wbx在被炸醒前可能挖到宝藏的最大数量。\n \u003cbr\u003e \n\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"输入包含多组数据. 每组数据包含两个正整数W和H.\n\u003cp\u003eH表示列数,W表示行数. W和H不超过20.\u003c/p\u003e\n\n\u003cbr\u003e每块地用字符表示如下:\n\u003cbr\u003e \n\u003cbr\u003e\u0027.\u0027 - 宝藏\n\u003cbr\u003e\u0027#\u0027 - 地雷\n\u003cbr\u003e\u0027@\u0027 - 起点(每组数据中只有一个,下面也有宝藏!)\n\u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"对于每组数据,输出一个整数,即wbx能挖到宝藏的最大数量。\n\u003cbr\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre\u003e6 9\n....#.\n.....#\n......\n......\n......\n......\n......\n#@...#\n.#..#.\n11 9\n.#.........\n.#.#######.\n.#.#.....#.\n.#.#.###.#.\n.#.#..@#.#.\n.#.#####.#.\n.#.......#.\n.#########.\n...........\n11 6\n..#..#..#..\n..#..#..#..\n..#..#..###\n..#..#..#@.\n..#..#..#..\n..#..#..#..\n7 7\n..#.#..\n..#.#..\n###.###\n...@...\n###.###\n..#.#..\n..#.#..\n0 0\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre\u003e45\n59\n6\n13\u003c/pre\u003e"}},{"title":"Hint","value":{"format":"HTML","content":"DFS"}}]}