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


int main() {
    
    int num_steps = 0; 
    string steps; 
    cin>> num_steps; 
    cin>>steps; 
    int num_valleys = 0; 
    int running_sum = 0; 
    bool in_valley = false; 

    for(int i = 0; i < num_steps; ++i){
        
        char in = steps[i]; 
        
        if(in == 'U'){
            running_sum += 1; 
            if(in_valley && running_sum == 0) ++num_valleys; 
        }
        
        if(in == 'D'){
            running_sum -= 1;
            if(running_sum == -1) in_valley = true; 
        }
    }
    cout<<num_valleys<<endl; 
}