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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    int n;
    string steps;
    cin >> n;
    cin >> steps;
    int i, valley = 0,status = 0, avail = 1;
    for (i = 0; i < n; i++) {
        if (steps[i] == 'U') {
            status++;
            if (status == 0)
                avail = 1;
        }
        else {
            status--;
            if(status < 0 && avail) {
                valley++;
                avail = 0;
            }
        }
    }
    cout << valley << endl;
    
    return 0;
}