#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, l, r) for (ll i = (l); i < (r); ++i)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pl = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vvvl = vector<vector<vector<ll>>>;
template<class T> using pq_ = priority_queue<T, vector<T>, greater<T>>;
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
using mint=modint998244353;
// g++ a.cpp -std=c++23 -I.
// g++ -std=c++23 -I. a.cpp -o main
// g++ -std=c++23 -I. anaive.cpp -o naive
// g++ -std=c++23 -I. agene.cpp -o gene



int main(){
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    ll n;
    cin>>n;
    string s;
    cin>>s;
    string r="HAPPY";
    ll ans=0;
    rep(i,n-5,n){
        if(s[i]!=r[i-(n-5)]){
            s[i]=r[i-(n-5)];
            ans++;
        }
    }
    rep(i,0,n-5){
        if(s.substr(i,5)==r){
            ans++;
        }
    }
    cout<<ans<<endl;
}