#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    int n;
    string s;
    cin >> n >> s;
    string h = "HAPPY";
    int ans = 0;
    rep(i, n - 9) {
        if (s.substr(i, 5) == h) {
            ans++;
        }
    }
    auto t = s.substr(n - 5, 5);
    rep(i, 5) {
        if (t[i] != h[i])
            ans++;
    }
    cout << ans << endl;

    return 0;
}