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


int main() {
    int n;
    scanf("%d\n", &n);
    int level = 0;
    bool valley = false;
    int res = 0;
    for (int i = 0; i < n; i++) {
        char c;
        scanf("%c", &c);
        if (c == 'U') level++;
        else level--;
        if (level < 0) valley = true;
        else {  // level >= 0
            if (valley) {
                res++;
                valley = false;
            }
        }
    }
    printf("%d\n", res);
    return 0;
}