{"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":"\u003cdiv class\u003d\"panel_content\"\u003e\r\n\tHey, welcome to \u003cspan data-scayt_word\u003d\"HDOJ\" data-scaytid\u003d\"1\"\u003eHDOJ\u003c/span\u003e(\u003cspan data-scayt_word\u003d\"Hangzhou\" data-scaytid\u003d\"2\"\u003eHangzhou\u003c/span\u003e \u003cspan data-scayt_word\u003d\"Dianzi\" data-scaytid\u003d\"3\"\u003eDianzi\u003c/span\u003e University Online Judge).\u003cbr /\u003e\r\n\t\u003cbr /\u003e\r\n\tIn this problem, your task is to calculate SUM(n) \u003d 1 + 2 + 3 + ... + n.\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003e\r\n\tThe input will consist of a series of integers n, one integer per line.\u003c/div\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003e\r\n\tFor each case, output SUM(n) in one line, followed by a blank line. You may assume the result will be in the range of 32-bit signed integer.\u003c/div\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003e\r\n\t\u003cpre\u003e\r\n\t\u003c/pre\u003e\r\n\t\u003cdiv style\u003d\"font-family:Courier New,Courier,monospace;\"\u003e\r\n\t\t\u003cpre\u003e\r\n\t\t1\r\n100 \u003c/pre\u003e\r\n\t\u003c/div\u003e\r\n\u003c/div\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cdiv class\u003d\"panel_content\"\u003e\r\n\t\u003cpre\u003e\r\n\t\u003c/pre\u003e\r\n\t\u003cdiv style\u003d\"font-family:Courier New,Courier,monospace;\"\u003e\r\n\t\t\u003cpre\u003e\r\n\t\t1\r\n\r\n5050 \u003c/pre\u003e\r\n\t\u003c/div\u003e\r\n\u003c/div\u003e"}}]}