#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 */   
    long long int n,i;    
    char inp;
    cin >> n;
    long long int stepcount=0, valcount=0;
    for(i=0; i<n; i++){
        cin >> inp;
        if(inp == 'D')
            stepcount--;
        if(inp == 'U'){
            if(stepcount == -1)
                valcount++;
            stepcount++;
        }
    }
    cout<<valcount;
    
    return 0;
}