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


int main() {
    int steps;
    cin >> steps;
    int valleys = 0;
    int elevation = 0;
    char step;
    for(int i = 0; i < steps; ++i) {
        cin >> step;
        if(step == 'U') {
            ++elevation;
        }
        if(step == 'D') {
            if(elevation == 0) {
                ++valleys;
            }
            --elevation;
        }
    }
    cout << valleys << endl;
    
    return 0;
}