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


int main() {
    int n;
    string str;
    cin >> n;
    cin >> str;
    
    int height = 0, count = 0;
    for (const auto& step : str) {
        if (step == 'U') {
            height++;
        } else if (step == 'D') {
            if (height == 0) count++;
            height--;
        }
    }
    
    cout << count;
    return 0;
}