#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    string s; cin >> s;
    string t = "HAPPY";
    int answer = 0;
    for(int i=0; i<5; i++){
        if(s.at(N-5+i) != t.at(i)) answer++;
        s.at(N-5+i) = t.at(i);
    }
    for(int i=0; i<N-5; i++){
        string s2 = s.substr(i,5);
        if(s2 == t) answer++,s.at(i+4) = 'X';
    }
    cout << answer << endl;
}