#include <iostream>

using namespace std;

int main()
{
    long long walks;
    cin >> walks;
    long long counter = 0;
    long long valleys = 0;
    string s;
    cin >> s;
    for(int i = 0;i < s.length();i++)
    {
        if(s[i] == 'U'){
            counter++;
        }else if(s[i] == 'D' && counter == 0){
            counter--; valleys++;}
        else if(s[i] == 'D' && counter != 0){
            counter--;
        }
    }
    cout << valleys;
    return 0;
}