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

int gettotalvalleys(vector<char> hike, int step)
{
    int down = 0;
    int up = 0;
    int valley_ctr = 0;
    bool valley_chk = false;
    
    
    for(int j = 0; j < step; j++)
    {
        if(hike[j] == 'D')
            down++;
        else
            up++;
           
        if(down > up  && valley_chk == false){
            valley_ctr++;
            valley_chk = true;
        }
        else if(up >= down) {
            valley_chk = false;
        }
        else {
            continue;
        }
        
    }      
    return valley_ctr;
}


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int steps, valleys;
    cin >> steps;
    vector<char> hike(steps);
    for(int i = 0; i < steps; i++){
        cin >> hike[i];
    }
    valleys = gettotalvalleys(hike, steps);
    cout << valleys;
}