#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 steps;
    cin >> steps;
    string hike;
    cin >> hike;
    int mountain =0 , valley = 0;
    int nvalleys = 0;
    int sealevel = 1;
    for(auto it = hike.begin(); it != hike.end(); it++)
     {
        //cout << "Got: " << *it << "Current state sealevel: " << sealevel << " mountain: " << mountain << " valley: " << valley << " nvalleys: " << nvalleys << "\n";
        if(sealevel)
        {
            if(*it == 'U')
            {
                mountain = 1;
                sealevel = 0;
            }
            else if(*it == 'D')
            {
                valley = 1;
                sealevel = 0;
                nvalleys++;
            }
        }
        else if(mountain)
        {
            if(*it == 'D')
            {
                if(--mountain == 0)
                    sealevel = 1;
            }
            else
                ++mountain;
        }
        else if(valley)
        {
            if(*it == 'U')
            {
                if(--valley == 0)
                    sealevel = 1;
            }
            else
                ++valley;
        }
    }
    cout << nvalleys << "\n";
    return 0;
}