#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <set>
#include <sstream>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    int32_t n;
    string s;
    cin >> n >> s;
    int32_t ans = 0;
    for (auto l = 0; l * 2 + 3 <= n; ++l) {
        int32_t i = 0, j = l + 1, k = l * 2 + 2;
        for (; k < n; ++i, ++j, ++k) {
            if (s[i] == 'U' && s[j] == 'M' && s[k] == 'G')
                ++ans;
        }
    }
    cout << ans << endl;
    return 0;
}