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


int main() {
    int n;
    cin>>n;
    int seaLevel=0;
    int count=0;
    int valley=false;
    char tempWalk;
    for(int i=0; i<n; i++) {
        cin>>tempWalk;
        if(tempWalk=='U') {
            seaLevel++;
            if(seaLevel==0&&valley==true) {
                count++;
                valley=false;
            }
        } else {
            seaLevel--;
            if(seaLevel<0){
                valley=true;
            }
        }
    }
    cout<<count;
    return 0;
}