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


int main() {
    int n;
    cin >> n;
    
    string s;
    cin >> s;
    
    int level = 0, ans = 0;
    for (int i = 0; i < n; ++i) {
        if (level == 0 && s[i] == 'D')
            ++ans;
        if (s[i] == 'D')
            --level;
        else 
            ++level;
    }
    
    cout << ans << endl;
    return 0;
}