#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;
    scanf(" %d",&n);
    int level = 0;
    int valleys = 0;
    char c;
    for(int i=0;i<n;i++)
    {
        scanf(" %c",&c);
        if(c=='U') level++;
        if(c=='D') {if(level==0)valleys++; level--;}
    }
    printf("%d",valleys);
    return 0;
}