{"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":"\nBiao Biao wants to drink w tins of beer. He has to take k seconds for the first tin of beer, 2*k seconds for the second tin of beer and so on(in other words, he has to spend i*k secons for the i-th tin of beer).\u003c/br\u003e\n\u003cbr\u003e\nBiao Biao has n seconds to drink beer before he express his true feelings for Zi Zi. So he wants to ask Zi Zi give him some seconds to drink up w tins of beer. How mang seconds does Biao Biao need ?\n\n\u003cdiv align\u003d\"center\"\u003e\u003cimg src \u003d \"https://s2.ax1x.com/2019/10/09/u5F14U.jpg\" width\u003d40% \u003e\u003c/div\u003e\n\u003cp text-algin\u003d\"center\"\u003e( HB: 我搂住你了,你别想跑!\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first line contains three positive integers \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ek\u003c/i\u003e, \u003ci\u003en\u003c/i\u003e, \u003ci\u003ew\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003ek\u003c/i\u003e, \u003ci\u003ew\u003c/i\u003e ≤ 1000\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e0 ≤ \u003ci\u003en\u003c/i\u003e ≤ 10\u003csup class\u003d\"upper-index\"\u003e9\u003c/sup\u003e\u003c/span\u003e), the cost of the first tin of beer, initial number of Biao Biao has and number of tins of beer he need to drink. \u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003eOutput one integer — the time that the Zi Zi should give HB. If he doesn\u0027t need to additional time, output \u003cspan class\u003d\"tex-span\"\u003e0\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\u003e3 17 4\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\u003e13\u003c/pre\u003e\n \u003c/div\u003e\n\u003c/div\u003e"}},{"title":"Limit","value":{"format":"HTML","content":"Time limit: 1000 ms \u0026emsp; Memory limit: 262144 kB\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e"}}]}