{"trustable":true,"sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv\u003e\u003cp\u003eUSTC campus network is a huge network. There is a bi-directional link between every pair of computers in the network. One of the computers is the BBS server, which is so popular that thousands of people log on it every day. Recently some links of the network are damaged by the rainstorm. The network administrator is going to check which computers are still connected with the BBS server directly or indirectly.\u003c/p\u003e\u003cp\u003eYou are to help the administrator to report the number of computers still connecting with the BBS server (not including itself).\u003c/p\u003e\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cdiv\u003e\u003cp\u003eThe input consists of multiple test cases. Each test case starts with a line containing two integers \u003ci\u003eN\u003c/i\u003e and \u003ci\u003eM\u003c/i\u003e (1 ≤ \u003ci\u003eN\u003c/i\u003e ≤ 10,000, 0 ≤ \u003ci\u003eM\u003c/i\u003e ≤ 1,000,000), which are the number of computers and the number of damaged links in USTC campus network, respectively. The computers are numbered from 1 to \u003ci\u003eN\u003c/i\u003e and computer 1 is the BBS server.\u003cbr\u003eEach of the following \u003ci\u003eM\u003c/i\u003e lines contains two integers \u003ci\u003eA\u003c/i\u003e and \u003ci\u003eB\u003c/i\u003e(1 ≤ \u003ci\u003eA\u003c/i\u003e ≤ \u003ci\u003eN\u003c/i\u003e, 1 ≤ \u003ci\u003eB\u003c/i\u003e ≤ \u003ci\u003eN\u003c/i\u003e, \u003ci\u003eA\u003c/i\u003e ≠ \u003ci\u003eB\u003c/i\u003e), which means the link between computer \u003ci\u003eA\u003c/i\u003e and \u003ci\u003eB\u003c/i\u003e is damaged. A link will appear at most once.\u003c/p\u003e\u003cp\u003eThe last test case is followed by a line containing two zeros. \u003c/p\u003e\u003c/div\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cdiv\u003e\u003cp\u003eFor each test case, print a line containing the test case number( beginning with 1) followed by the number of computers still connecting with the BBS server.\u003c/p\u003e\u003c/div\u003e"}},{"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\u003e3 2\r\n1 2\r\n1 3\r\n4 3\r\n1 2\r\n3 2\r\n4 2\r\n0 0\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003eCase 1: 0\r\nCase 2: 2\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}