#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ll n;
  string s;
  cin >> n >> s;
  const string str = "HAPPY";
  ll ans = 0;
  for (int i = 5; i > 0; i--) {
    if (s[n - i] != str[5 - i]) {
      ans++;
      s[n - i] = str[5 - i];
    }
  }
  for (int i = 0; i < n - 5; i++) {
    // if (i != n - 5) {
    bool ok = false;
    for (int j = 0; j < 5; j++) {
      if (s[i + j] != str[j]) {
        ok = true;
      }
    }
    if (!ok) {
      ans++;
    }
    //}
  }
  cout << ans << "\n";
}