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


int main() {
    int n=0, level=0, valleys=0;
    bool valley_start = false;
    cin>>n;
    vector<char> steps(n);
    for (int i=0; i<n; i++) {
        cin>>steps[i];
        if (steps[i]=='U') level++;
        if (steps[i]=='D') level--;
        
        if ((level < 0) && (!valley_start))
            valley_start = true;
        else if ((level >= 0) && (valley_start)) {
            valleys++;
            valley_start = false;
        }
        
        // cout<<steps[i]<<":"<<level<<":"<<valleys<<":"<<valley_start<<endl;
    }
    
    cout<<valleys<<endl;
    return 0;
}