{"trustable":false,"sections":[{"title":"","value":{"format":"HTML","content":"\u003clink href\u003d\"css/light_oj.css\" rel\u003d\"stylesheet\" type\u003d\"text/css\" /\u003e\n\u003cp class\u003d\"MsoNormal\"\u003e\n\tGiven two integers: \u003cb\u003en\u003c/b\u003e and \u003cb\u003em\u003c/b\u003e and \u003cb\u003en\u003c/b\u003e is divisible by \u003cb\u003e\u003cspan data-scayt_word\u003d\"2m\" data-scaytid\u003d\"1\"\u003e2m\u003c/span\u003e\u003c/b\u003e, you have to write down the first \u003cb\u003en\u003c/b\u003e natural numbers in the following form. At first take first \u003cb\u003em\u003c/b\u003e integers and make their sign negative, then take next \u003cb\u003em\u003c/b\u003e integers and make their sign positive, the next \u003cb\u003em\u003c/b\u003e integers should have negative signs and continue this procedure until all the \u003cb\u003en\u003c/b\u003e integers have been assigned a sign. For example, let \u003cb\u003en\u003c/b\u003e be \u003cb\u003e12\u003c/b\u003e and \u003cb\u003em\u003c/b\u003e be \u003cb\u003e3\u003c/b\u003e. Then we have\u003c/p\u003e\n\u003cp class\u003d\"MsoNormal\"\u003e\n\t\u003cb\u003e-1 -2 -3\u003c/b\u003e +4 +5 +6 \u003cb\u003e-7 -8 -9\u003c/b\u003e +10 +11 +12\u003c/p\u003e\n\u003cp class\u003d\"MsoNormal\"\u003e\n\tIf \u003cb\u003en \u003d 4\u003c/b\u003e and \u003cb\u003em \u003d 1\u003c/b\u003e, then we have\u003c/p\u003e\n\u003cp class\u003d\"MsoNormal\"\u003e\n\t\u003cb\u003e-1\u003c/b\u003e +2 \u003cb\u003e-3\u003c/b\u003e +4\u003c/p\u003e\n\u003cp class\u003d\"MsoNormal\"\u003e\n\tNow your task is to find the summation of the numbers considering their signs.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp class\u003d\"MsoNormal\"\u003e\n\tInput starts with an integer \u003cb\u003eT (\u003c/b\u003e\u003cb\u003e\u0026le; 10000)\u003c/b\u003e, denoting the number of test cases.\u003c/p\u003e\n\u003cp class\u003d\"MsoNormal\"\u003e\n\tEach case starts with a line containing two integers: \u003cb\u003en\u003c/b\u003e and \u003cb\u003em (2 \u0026le; n \u0026le; 10\u003csup\u003e9\u003c/sup\u003e, 1 \u0026le; m)\u003c/b\u003e. And you can assume that \u003cb\u003en\u003c/b\u003e is divisible by \u003cb\u003e2*m\u003c/b\u003e.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp class\u003d\"MsoNormal\"\u003e\n\tFor each case, print the case number and the summation.\u003c/p\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cp class\u003d\"MsoNoSpacing\"\u003e\n\t\u003cspan style\u003d\"font-family:\u0026quot;Courier New\u0026quot;\"\u003e2\u003c/span\u003e\u003c/p\u003e\n\u003cp class\u003d\"MsoNoSpacing\"\u003e\n\t\u003cspan style\u003d\"font-family:\u0026quot;Courier New\u0026quot;\"\u003e12 3\u003c/span\u003e\u003c/p\u003e\n\u003cp class\u003d\"MsoNoSpacing\"\u003e\n\t\u003cspan style\u003d\"font-family:\u0026quot;Courier New\u0026quot;\"\u003e4 1\u003c/span\u003e\u003c/p\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cp class\u003d\"MsoNoSpacing\"\u003e\n\t\u003cspan style\u003d\"font-family:\u0026quot;Courier New\u0026quot;\"\u003eCase 1: 18\u003c/span\u003e\u003c/p\u003e\n\u003cp class\u003d\"MsoNoSpacing\"\u003e\n\t\u003cspan style\u003d\"font-family:\u0026quot;Courier New\u0026quot;\"\u003eCase 2: 2\u003c/span\u003e\u003c/p\u003e"}},{"title":"Hint","value":{"format":"HTML","content":"\u003cp\u003e\n\tFind formula\u003c/p\u003e"}}]}