#include using namespace atcoder; #include template inline bool chmin(T&a, T b){if(a > b){a = b; return true;}else{return false;}} template inline bool chmax(T&a, T b){if(a < b){a = b; return true;}else{return false;}} #define ll long long #define double long double #define rep(i,n) for(int i=0;i<(n);i++) #define REP(i,n) for(int i=1;i<=(n);i++) #define mod (ll)(1e9+7) #define inf (ll)(3e18+7) #define eps (double)(1e-9) #define pi (double) acos(-1) #define all(x) x.begin(),x.end() #define rall(x) x.rbegin(),x.rend() using namespace std; int main() { int n; string s; cin >> n >> s; int ans = 0; rep(i, n){ if(s.substr(i, 5) == "CPCTF"){ ans++; i += 4; }else if(s.substr(i, 7) == "CPCTCPC"){ ans++; i += 6; } } cout << ans << endl; }