import java.util.Scanner; public class Main{ public static void main(String[] args) { Scanner sc = new Scanner(System.in); char[] chars = sc.nextLine().toCharArray(); String str = ""; for (int i = 0;i<chars.length;i++){ if (!str.contains(chars[i]+"")){ str+=chars[i]; } } System.out.println(str.length()); } }