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

int str_to_int(string &s) {
    int num;
    istringstream ss(s);
 
    if (!(ss >> num)) {
        return 0;
    }
    return num;
}

int main() {
    string stps, sequence;
    int seaLevel=0,totalSteps, current=0, valleys=0;
    bool below = false;
    
    getline(cin,stps);
    getline(cin, sequence);
    
    totalSteps = str_to_int(stps);

    current = seaLevel;
    for(int i=0;i<totalSteps;++i) {
        if (sequence.at(i) == 'U') {
            current++;
        }
        else {
            current--;
        }
        if (current < 0 && below == false) {
            valleys++;
            below = true;
        }
        if (current >=0 && below == true) {
            below = false;
        }
    }
    cout << valleys;
    
    return 0;
}