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


int main() {
    int N;
    cin >> N;
    
    int ret = 0;
    int height = 0;
    bool inV = false;

    while (N--) {
        char m;
        cin >> m;

        if (m == 'U') {
            if (height == 0) {
                inV = false;
            }
            height++;  
        } else {
            if (height == 0) {
                inV = true;
                ret++;
            }
            height--;
        }
    }
    cout << ret;
    return 0;
}