#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 n,level=0,m=0,v=0,count=0;
    cin>>n;
    char step[n];
    for(int i=0;i<n;i++){
        cin>>step[i];
        if(step[i]=='U' and level==0){//start of mountain
            level++;
            m=1;
        }
        else if(step[i]=='U'){
            if(m==1){//on mountain
                level++;
            }   
            if(v==1){
                level--;
                if(level==0){
                    v=0;
                    count++;
                }
            }
        }
        else if(step[i]=='D' and level==0){
            v=1;
            level++;
        }
        else if(step[i]=='D'){
            if(m==1){//going down from m
                level--;
                if(level==0){
                    m=0;
                }
            }
            if(v==1){
                level++;
            }
        }
        
    }
    cout<<count;
    return 0;
}