#include <iostream> #include <cstring> #include <algorithm> #include <vector> #include <string> #include <math.h> #include <iomanip> #include <limits> #include <list> #include <queue> #include <tuple> #include <map> using namespace std; #define MOD (long long int)(1e9+7) #define ll long long int #define rep(i,n) for(int i=0; i<(int)(n); i++) #define reps(i,n) for(int i=1; i<=(int)(n); i++) #define REP(i,n) for(int i=n-1; i>=0; i--) #define REPS(i,n) for(int i=n; i>0; i--) #define INF (int)(1123456789) #define LINF (long long int)(112345678901234567) int main(void){ int n; string s; cin>>n; cin>>s; ll ans; rep(i,n-2){ for(int j=i+1;j<n-1;j++){ if(s[i] == 'U' && s[j] == 'M' && j+j-i < n && s[j+j-i] == 'G'){ ans++; } } } cout<<ans<<endl; return 0; }