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

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. */
        Scanner scan = new Scanner(System.in);
        int numSteps = Integer.parseInt(scan.nextLine());
        int numValleys = 0;
        int elevation = 0;
        String pathString = scan.nextLine();
        scan.close();
        
        for(int i = 0; i < numSteps; i++){
            if(pathString.charAt(i) == 'D'){
                if(elevation == 0){
                    numValleys++;
                }
                elevation--;
            }else{
                elevation++;
            }
        }
        
        System.out.print(numValleys);
    }
}