#include <iostream>
#include <vector>

int main() {
    using namespace std;
    int n;
    string s;
    cin >> n >> s;

    string happy = "HAPPY";
    int ans = 0;
    for (int i = 0; i < 5; i++) {
        if (s[i + n - 5] != happy[i]) {
            s[i + n - 5] = happy[i];
            ans++;
        }
    }

    for (int i = 0; i < n - 5; i++) {
        bool is_happy = true;
        for (int j = 0; j < 5; j++) {
            if (s[i + j] != happy[j]) {
                is_happy = false;
                break;
            }
        }
        if (is_happy) { ans++; }
    }
    cout << ans << endl;
}