#include <bits/stdc++.h>
using namespace std;
//#include<atcoder/all>
//using namespace atcoder;
using ll = long long int;
using ull = unsigned long long int;
using ld = long double;
constexpr ll MAX = 2000000000000000000;
constexpr ld PI = 3.14159265358979;
constexpr ll MOD = 0;//2024948111;
ld dotorad(ld K){ return PI * K / 180.0; }
ld radtodo(ld K){ return K * 180.0 / PI; }
mt19937 mt;
void randinit(){ srand((unsigned)time(NULL));mt = mt19937(rand()); }
int main(){
    ll N;
    cin >> N;
    string S;
    cin >> S;
    string T = "";
    for(ll i = 0;i < (ll)S.size();i++){
        T += S[i];
        if((ll)T.size() >= 7){
            string tgt = "CPCTCPC";
            bool ok = 1;
            for(ll j = 0;j < 8;j++){
                if(T[(ll)T.size() - (ll)tgt.size() + j] != tgt[j]){
                    ok = 0;
                    break;
                }
            }
            if(ok){
                T.pop_back();
                T.pop_back();
                T.pop_back();
                T += "F";
            }
        }
    }
    ll ans = 0;
    string tgt = "CPCTF";
    for(ll i = 0;i <= (ll)T.size() - (ll)tgt.size();i++){
        bool ok = 1;
        for(ll j = 0;j < (ll)tgt.size();j++){
            if(T[i + j] != tgt[j]){
                ok = 0;
                break;
            }
        }
        if(ok) ans++;
    }
    cout << ans << endl;
}