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

第一行包含两个数：一个正整数n（0<n<=50）表示字符串长度，一个正整数m（0个数。

youdao

Supply an integer, n, for the third argument to return only the first n matches; or supply -1 for all matches.

给第三个参数提供整数n将只返回前 n 个匹配；或者提供-1 返回所有匹配。

youdao

Supply an integer, n, for the third argument to return only the first n matches; or supply -1 for all matches.

给第三个参数提供整数n将只返回前 n 个匹配；或者提供-1 返回所有匹配。

youdao