#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;
    cin>>n;
    char c;
    int s=0,v=0;
    for(int i=0;i<n;i++){
        cin>>c;
        if(c=='U'){
            s++;
        }
        else if(s>0){
            s--;
        }
        else{
            if(s==0)
                v++;
            s--;
        }
    }
    cout<<v;
    return 0;
}