#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int findValleys(vector <char> s){
    int h=0,d=0,nValley=0;
    for(int i=0;i<s.size();i++){
        //cout << s[i];
        if (s[i] == 'U' && d==0){
            h++;
        }
        if (s[i] == 'D' && h==0){
            d++;
        }
        if (s[i] == 'U' && d>0){
            if(d==1){
                nValley++;
            }
            d--;
        }
        if (s[i] == 'D' && h>0){
            h--;
        }
    }
    //cout << nValley;
    return nValley;
}


int main() {
    int n;
    cin >> n;
    cin.ignore (std::numeric_limits<std::streamsize>::max(), '\n'); 
    vector<char> steps;
    char step;
    for(int i=0; i<n; i++) {
        cin >> step;
        steps.push_back(step);
    }
    cout << findValleys(steps);
    return 0;
}