#include<bits/stdc++.h>
using namespace std;
int main()
{
    string s2;
    cin>>s2;
    string s;
    int c=0,countv=0;
    cin>>s;
    for(int i=0;i<s.size();i++)
    {
        if(s[i]=='U')
            c++;
        else
            c--;
        if(c==0&&s[i]=='U')
            countv++;
    }
    cout<<countv<<endl;
return 0;
}