{"trustable":false,"sections":[{"title":"","value":{"format":"HTML","content":"题意：给定一张无向图，求其中权值最小的一座桥，派最少的士兵去炸掉它！！"}},{"title":"Input","value":{"format":"HTML","content":"There are no more than 12 test cases. \n\u003cbr\u003e \n\u003cbr\u003eIn each test case: \n\u003cbr\u003e \n\u003cbr\u003eThe first line contains two integers, N and M, meaning that there are N islands and M bridges. All the islands are numbered from 1 to N. ( 2 \u0026lt;\u003d N \u0026lt;\u003d 1000, 0 \u0026lt; M \u0026lt;\u003d N \n\u003csup\u003e2\u003c/sup\u003e ) \n\u003cbr\u003e \n\u003cbr\u003eNext M lines describes M bridges. Each line contains three integers U,V and W, meaning that there is a bridge connecting island U and island V, and there are W guards on that bridge. ( U ≠ V and 0 \u0026lt;\u003d W \u0026lt;\u003d 10,000 ) \n\u003cbr\u003e \n\u003cbr\u003eThe input ends with N \u003d 0 and M \u003d 0."}},{"title":"Output","value":{"format":"HTML","content":"For each test case, print the minimum soldier number Zhou Yu had to send to complete the mission. If Zhou Yu couldn\u0027t succeed any way, print -1 instead."}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre\u003e3 3\n1 2 7\n2 3 4\n3 1 4\n3 2\n1 2 7\n2 3 4\n0 0\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre\u003e-1\n4\u003c/pre\u003e"}}]}