#include<iostream>
#include<algorithm>
#include <vector>
#include<cmath>
#include<iomanip>
#include<queue>
using namespace std;
typedef long long int lont;
int main() {
	int N;
	string S;
	cin >> N >> S;
	vector<char>vec(N * 3);
	for (int ia = 0; ia < N; ia++) {
		vec.at(ia) = S.at(ia);
	}
	int cnt = 0;
	for (int ib = 0; ib < N; ib++) {
		for (int ic = 0; ic < N; ic++) {
			if (vec.at(ic) == 'U'
				&& vec.at(ic + ib) == 'M'
				&& vec.at(ic + 2 * ib) == 'G') {
				cnt++;
			}
		}
	}
	cout << cnt << endl;
}