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


int main() {
     int n,nr=0,niv=0,ok=0;
       char c;
     cin>>n;
    for(int i=1;i<=n;i++)
        {cin>>c;
         if (c=='D') niv--;
             else niv++;
         if(niv>=0) {ok=0;}
            else { if (ok==0) nr ++;
                    ok=1;
                  
                }
         
    }
    cout<<nr;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}