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. */
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        String walk = scan.next();
        int count = 0;
        int vallies = 0;
        for(int i=0; i<n; i++) {
            char temp = walk.charAt(i);
            String move = Character.toString(temp);
            if(move.equals("D") && count == 0) {
                count--;
                vallies++;
                continue;
            } else if(move.equals("D")){
                count--;
                continue;
            } else {
                count++;
                continue;
            }
        }
        System.out.println(vallies);
    }
}