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


int main() {
   int n,i,sea_level=0,valley=0;
    cin>>n;
    char s[n];
    for(i=0;i<n;++i)
        cin>>s[i];
   
    for(i=0;i<n;++i)
        {
            if(s[i]=='U')
            sea_level++;
            else
            {
                --sea_level;
                if(sea_level==-1)
                    valley++;
             }
    }
    cout<<valley<<endl;
    
    return 0;
}