import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        int n = input.nextInt();

        int counter = 0;
        int valleyCounter = 0;

        boolean valleyFlag = false;
        boolean upFlag = false;

        String s = input.next();
        char[] steps = s.toCharArray();

        for (int i = 0; i < n; i++) {
            char step = steps[i];

            if (step == 'D') {
                counter--;
            } else {
                counter++;
                upFlag = true;
            }

            if (counter < 0 && !valleyFlag) {
                valleyFlag = true;
            } else if (counter == 0 && valleyFlag && upFlag) {
                valleyCounter++;
                upFlag = false;
                valleyFlag = false;
            }
        }

        System.out.println(valleyCounter);
    }
}