#include <bits/stdc++.h>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int N; cin >> N;
    string s; cin >> s;

    string s2 = "";
    for(int i=0; i<N; i++){
        string t = s.substr(i,3);
        if(t == "CPC" && i >= 4 && i < N-2){
            string t2 = s2.substr(i-4,4);
            if(t2 == "CPCT") s2 += 'F',i += 2;
            else s2 += s.at(i);
        }
        else s2 += s.at(i);
    }

    int answer = 0;
    for(int i=0; i<(int)s2.size()-4; i++){
        string s3 = s2.substr(i,5);
        if(s3 == "CPCTF") answer++;
    }
    cout << answer << endl;
}