#include <bits/stdc++.h>

using namespace std;

constexpr string T = "HAPPY";

int main() {
  int N;
  cin >> N;
  string S;
  cin >> S;
  int ret = 0;
  for (int i = 0; i < 5; i++) {
    ret += S[N - 5 + i] != T[i];
  }
  for (int i = 0; i + 5 <= N - 5; i++) {
    if (S.substr(i, 5) == T) {
      ret++;
    }
  }
  cout << ret << endl;
}