#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <stdio.h>
using namespace std;
#define int long long
int MOD = 1000000007;
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int N;
	cin >> N;
	string S;
	cin >> S;
	int res = 0;
	for (int i = 0; i < N; i++) {
		if (S[i] == 'M') {
			for (int j = 1; i - j >= 0 && i + j < N; j++) {
				if (S[i - j] == 'U' && S[i + j] == 'G')res++;
			}
		}
	}

	cout << res << endl;
}