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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n = 0;
    string steps;
    cin >> n;
    cin >> steps;
    
    int valleys = 0;
    int height = 0; //sea level
    bool inValley = false;
    int i=0;
    for (auto c : steps) {
        if (c == 'D')
            --height;
        else
            ++height;
        if (height == -1 && !inValley) {
            inValley = true;
            ++valleys;
        }
        else if (height == 0)
            inValley = false;
        if (++i == n)
            break;
    }
    cout << valleys << endl;
    return 0;
}