#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
  int n;
  cin >> n;
  string s;
  cin >> s;
  int ans = 0;
  string tmp = s.substr(n - 5, 5);
  string sign = "HAPPY";
  for (int i = 0; i < 5; ++i) ans += sign[i] != tmp[i];
  n -= 5;
  for (int i = 0; i + 5 <= n; ++i)
  {
    tmp = s.substr(i, 5);
    if (tmp == sign)
    {
      s[i + 4] = 'B';
      ++ans;
    }
  }  
  cout << ans << endl;
}