{"trustable":false,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e\n .input, .output {\n border: 1px solid #888888;\n }\n .output {\n margin-bottom: 1em;\n position: relative;\n top: -1px;\n }\n .output pre, .input pre {\n background-color: #EFEFEF;\n line-height: 1.25em;\n margin: 0;\n padding: 0.25em;\n }\n \u003c/style\u003e\n \u003clink rel\u003d\"stylesheet\" href\u003d\"//codeforces.org/s/96598/css/problem-statement.css\" type\u003d\"text/css\" /\u003e\n\u003cscript\u003e\n window.katexOptions \u003d {\n delimiters: [\n {left: \u0027$$$$$$\u0027, right: \u0027$$$$$$\u0027, display: true},\n {left: \u0027$$$\u0027, right: \u0027$$$\u0027, display: false},\n {left: \u0027$$\u0027, right: \u0027$$\u0027, display: true},\n {left: \u0027$\u0027, right: \u0027$\u0027, display: false}\n ]\n };\n\u003c/script\u003e\n","sections":[{"title":"","value":{"format":"HTML","content":"\u003cstyle type\u003d\u0027text/css\u0027\u003e .input, .output {border: 1px solid #888888;} .output {margin-bottom:1em;position:relative;top:-1px;} .output pre,.input pre {background-color:#EFEFEF;line-height:1.25em;margin:0;padding:0.25em;} .title {background-color:#FFFFFF;border-bottom: 1px solid #888888;font-family:arial;font-weight:bold;padding:0.25em;} \u003c/style\u003e \u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027]], displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027]]}\n });\n \u003c/script\u003e\n \u003cscript type\u003d\"text/javascript\" async\n src\u003d\"https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config\u003dTeX-AMS-MML_HTMLorMML\"\u003e\n \u003c/script\u003e\n\u003cp\u003eRony is addicted to computer games. Now-a-days, Rony is playing a popular computer game \"World of Grid\". In this game, the world map is a rectangle with \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e columns and \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003em\u003c/i\u003e\u003c/span\u003e rows. A town, wilderness or mountains can be found in each of the map\u0027s cell. Furthermore, any non-mountain cell that is border-adjacent to a town is wilderness, and any non-mountain cell that is border-adjacent to wilderness is a town. Players can move between border-adjacent cells, but cannot enter mountain cells. It costs \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e\u003c/span\u003e gold to move from wilderness to a town, and it costs \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eb\u003c/i\u003e\u003c/span\u003e gold to move from a town to wilderness.\u003c/p\u003e\n\u003cp\u003eInitially Rony is in the top left cell of the map, which is a town. Rony wants to move to the bottom right cell of the map. Help Rony find the minimum amount of gold he needs to do this.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first line of the input contains two integers \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e and \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003em\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003en\u003c/i\u003e, \u003ci\u003em\u003c/i\u003e ≤ 500\u003c/span\u003e)\u0026nbsp;— the width and the height of the map. The second line contains two integers \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ea\u003c/i\u003e\u003c/span\u003e and \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eb\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e0 ≤ \u003ci\u003ea\u003c/i\u003e, \u003ci\u003eb\u003c/i\u003e ≤ 1000\u003c/span\u003e)\u0026nbsp;— the cost of entering a town and the cost of entering wilderness.\u003c/p\u003e\n\u003cp\u003eThe next \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003em\u003c/i\u003e\u003c/span\u003e lines each contain a string of \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e characters. The \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ei\u003c/i\u003e\u003c/span\u003e-th character in the \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ej\u003c/i\u003e\u003c/span\u003e-th string contains \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e.\u003c/span\u003e\" if the corresponding cell can be occupied by a player and \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e#\u003c/span\u003e\" if it is a mountain cell.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003eThe output should contain a single integer\u0026nbsp;— the minimum amount of gold needed to move to the bottom right cell. If it is impossible, print \"\u003cspan class\u003d\"tex-font-style-tt\"\u003eIMPOSSIBLE\u003c/span\u003e\".\u003c/p\u003e"}},{"title":"Examples","value":{"format":"HTML","content":"\u003cdiv class\u003d\"sample-test\"\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e5 3\u003cbr\u003e1 2\u003cbr\u003e.#...\u003cbr\u003e.#.#.\u003cbr\u003e...#.\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"output\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Output\n \u003c/div\u003e\n \u003cpre\u003e15\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e3 3\u003cbr\u003e4 5\u003cbr\u003e..#\u003cbr\u003e.#.\u003cbr\u003e#..\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"output\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Output\n \u003c/div\u003e\n \u003cpre\u003eIMPOSSIBLE\u003c/pre\u003e\n \u003c/div\u003e\n\u003c/div\u003e"}}]}