import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        int numValleys = 0;
        int seaLevel = 0;
        Boolean valley = false;
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String line = in.next();
        for (int i = 0; i < n; i++){
            if(line.charAt(i) == 'D'){
                seaLevel --;
            }
            else {
                seaLevel ++;
            }
            if (valley && seaLevel == 0) {
            	numValleys++;
            }
            if (seaLevel < 0) {
            	valley = true;
            }
            else {
            	valley = false;
            }

        }
        System.out.println(numValleys);
    }

}