import java.util.Scanner;

public class Main {
  public static void log(Object obj) {
    System.out.println(obj.toString());
  }

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    char[] c = s.toCharArray();
    log(c[0] == c[1] && c[1] != c[2]?"Yes":"No");
  }
}