{"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\"\u003eThe annual Games in frogs\u0027 kingdom started again. The most famous game is the Ironfrog Triathlon. One test in the Ironfrog Triathlon is jumping. This project requires the frog athletes to jump over the river. The width of the river is L (1\u0026lt;\u003d L \u0026lt;\u003d 1000000000). There are n (0\u0026lt;\u003d n \u0026lt;\u003d 500000) stones lined up in a straight line from one side to the other side of the river. The frogs can only jump through the river, but they can land on the stones. If they fall into the river, they \u003cbr\u003eare out. The frogs was asked to jump at most m (1\u0026lt;\u003d m \u0026lt;\u003d n+1) times. Now the frogs want to know if they want to jump across the river, at least what ability should they have. (That is the frog\u0027s longest jump distance). \u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"The input contains several cases. The first line of each case contains three positive integer L, n, and m. \u003cbr\u003eThen n lines follow. Each stands for the distance from the starting banks to the nth stone, two stone appear in one place is impossible. "}},{"title":"Output","value":{"format":"HTML","content":"For each case, output a integer standing for the frog\u0027s ability at least they should have. "}},{"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 1 2\r\n2\r\n25 3 3\r\n11 \r\n2\r\n18\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e4\r\n11\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}