给定一个字符串S[1..n]和一个整数T，现在需要在字符串S中找出长度不小于T的一个子串，

使得其在原串中不重叠出现的次数最多，求这个次数。

Input

第一行：一个整数T(T > 1)

第二行：一个字符串S，且仅包含小写字母，字符串长度不超过10000

Output

一个整数。代表出现最多的次数

如果没有满足条件的解则输出0-Given a string S [1 .. n] and an integer T, now need to find the length of the string S is not less than T, a sub-string, making it in the original string does not overlap occurs more frequently than to seek the number of times. Input The first line: an integer T (T>　1) second line: a string S, and contains only lowercase letters, the string length does not exceed 10000 Output an integer. Appears most representative of the number of times, if the solution does not meet the conditions, the output 0