{"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/3.0.1/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 一只小虫,虫在井底,井有 n 英寸深。它有足够的能量每分钟爬上 u 英寸,但在再次爬上之前,必须休息一分钟。在休息的过程中,它下滑了 d 英寸。攀爬和休息的过程会重复。虫子多久才能爬出井外?我们总是把一分钟的一部分算作整整一分钟,如果蠕虫在爬行结束时刚刚到达井顶,我们就认为蠕虫爬出了井。\n \u003cbr\u003e \n\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"将会有多个问题实例,每一行将包含 3 个正整数 n、u 和 d。它们给出了上段中提到的数值。此外,你可以假设 d \u003c u,n \u003c 100。n \u003d 0 表示输出结束。\n\u003cbr\u003e"}},{"title":"Output","value":{"format":"HTML","content":"每个输入实例都应该在一行上生成一个整数,表示虫子爬出井口所需的分钟数。\n\u003cbr\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre\u003e10 2 1\n20 3 1\n0 0 0\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre\u003e17\n19\u003c/pre\u003e"}}]}