第一行包含两个数：一个正整数n（050）表示字符串长度，一个正整数m（0个数。

The first line contains two integers: a positive integer n (0 50) giving the length of the strings; and a positive integer m (0 number of strings.

youdao

输入以一个正整数开始，它占一行，本身代表的是下面这种情形的数目，每一个都按下面的要求描述。

The input begins with a single positive integer on a line by itself indicating the number of the cases following, each of them as described below.

youdao

输入以一个正整数开始，它占一行，本身代表的是下面这种情形的数目，每一个都按下面的要求描述。

The input begins with a single positive integer on a line by itself indicating the number of the cases following, each of them as described below.

youdao