#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 numSteps;
    cin >> numSteps;
    
    int level = 0;
    int valleyCount = 0;
    char step;
    bool inValley = false;
    
    while (cin >> step) {        
        if (level < 0) {
            inValley = true;
        }
        
        if (step == 'U') {
            level++;
            if (level == 0) {
                inValley = false;
                valleyCount++;
            }
        } else {
            level--;
        }
    }
    
    cout << valleyCount;
    
    return 0;
}