#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define fi first
#define se second
typedef pair<ll,ll> P;
#define Mod 1000000007
using VP = vector<P>; using VVP = vector<VP>;
using VI = vector<ll>; using VVI = vector<VI>; using VVVI = vector<VVI>;

int main(){
    ll i,j;
    ll n;
    string s;
    cin>>n>>s;
    ll ans=0;

    for(i=0;i<n;i++){
        for(j=0;j<i;j++){
            if(i*2-j<=n-1){
                if(s[i]=='M'&&s[j]=='U'&&s[2*i-j]=='G') ans++;
            }
        }
    }
    cout<<ans<<endl;
    
    return 0;
}