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


int main() {
    int N;
    int lv = 0;
    bool valley;
    int c=0;
    char ch;
    
    cin >> N;
    while(--N){
        cin >> ch;
            
        if(ch == 'U')lv++;
        else lv--;
        
        if(lv<0) valley=true;
        else valley=false; 
        
        if(lv== -1 && ch=='D' && valley) c++;
        
    }
    cout << c << endl;
    return 0;
}