#include <bits/stdc++.h>
using namespace std;
int main (){
    int N,ans=0;
    string s,sb;
    cin >> N >> sb;
    s = "A"+sb;
    for(int i=1;i<s.size()-2;i++){
        if(s.at(i) == 'U'){
            for(int j=i+2;j<s.size();j += 2){
                if(s.at(j)=='G'&&s.at((i+j)/2) == 'M'){
                ans++;
                }
            }
        }
    }
    cout << ans << endl;
}