给出m个字符串，要求输出重复出现n次的字符串有几个。
先给顶一个N，N<=100000，接着输入N个字符串。
对于每组测试数据，输出若干行，每行两个正整数，第一个数表示重复的次数，第二个数表示在此重复次数下有几种不同的字符串。
For each test case, print "Case K:" where K is the Kth case. K begins with 1. Then print the times(T) a string appears and the number(M) of strings that appear T times. Don't print T or M where M<=0. The output is ordered by T. The length of each strings won't longer than 20.