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) { Scanner in = new Scanner(System.in); int n = in.nextInt(); String s = in.next(); int valeys = 0; int level = 0; for(int i=0; i<s.length(); i++){ if(s.charAt(i)=='D'){ if(level==0){ valeys++; } level--; } else{ level++; } } System.out.println(valeys); } }