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


int main() {
    int n;
    cin >> n;
    int level = 0;
    int nValleys = 0;
    string s;
    cin >> s;
    for(string::size_type i = 0; i < s.size(); ++i) {
        int prevLevel = level;
        if (s[i] == 'D')
            level--;
        else
            level++;
        
        if (prevLevel == -1 && level == 0)
            nValleys++;
        
    }
    cout << nValleys << endl;
    return 0;
}