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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    char s[1000001];
    long long n,sum=0,flag=0,valley=0;
    cin>>n;
    for(long long i=0;i<n;i++){
        cin>>s[i];
        if(s[i]=='U')
            sum++;
        else
            sum--;
        if(sum<0)
            flag=1;
        if(sum==0&&flag!=0){
            flag=0;
            valley++;
        }
    }
    cout<<valley;
    return 0;
}