Down the Hatch!

#include <iostream>
#include <string>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;

int main()
{
    int n;
    string s;
    cin >> n;
    getline(cin, s);
    getline(cin, s);
    int ans = 0;
    for (int i = n; i < s.length(); i += n)
        if (s[i - 1] == s[i - 2] && s[i - 2] == s[i - 3])
            ++ans;
    cout << ans << endl;
    return 0;
}