/* -*- coding: utf-8 -*-
 *
 * 3757.cc:  No.3757 Happy End - yukicoder
 */

#include<cstdio>
#include<cstring>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 300000;
const int L = 5;
const char p[] = "HAPPY";

/* typedef */

/* global variables */

char s[MAX_N + 4];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d%s", &n, s);

  int sum = 0;
  for (int i = 0; i < L; i++)
    if (s[n - L + i] != p[i]) sum++;
  copy(p, p + L, s + (n - L));
  
  for (int i = 0; i < n - L;) {
    if (! strncmp(s + i, p, L)) s[i + L - 1] = 'Z', sum++, i += L;
    else i++;
  }

  printf("%d\n", sum);

  return 0;
}