#include <iostream>
using namespace  std;

int main() {
    int n;
    cin >> n;
    int kolku_patiki = 0;
    long long vleckanja = 0;
    for(int i = 0; i < n; i++) {
        string s;
        cin >> s;
        if(s == "LL") {
            kolku_patiki++;
        }
        if(s == "DD") {
            kolku_patiki--;
        }
        vleckanja += abs(kolku_patiki);
    }
    cout << vleckanja << endl;
    return 0;
}