#include<bits/stdc++.h>

using namespace std;

int main(){
	int n;
	string s;
	string happy="HAPPY";
	cin >> n;
	cin >> s;
	
	string str1 = s.substr(0,n-5);
	string str2 = s.substr(n-5);
	
	int ans = 0;
	for(int i=0;i < n-5;i++){
		string ss = str1.substr(i,5);
		if(ss == happy) ans++;
	}
	
	for(int i=0;i < 5;i++){
		if(str2[i] != happy[i]) ans++;
	}
	
	cout << ans << endl;
}