import java.util.Scanner;
public class Main{
 public static void main(String[] args){
   Scanner sc = new Scanner(System.in);
   String S = sc.next();
   if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   }
  
 }
} import java.util.Scanner; Scanner java.util public class Main{
 public static void main(String[] args){
   Scanner sc = new Scanner(System.in);
   String S = sc.next();
   if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   }
  
 }
} Main public static void main(String[] args){
   Scanner sc = new Scanner(System.in);
   String S = sc.next();
   if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   }
  
 } main {
   Scanner sc = new Scanner(System.in);
   String S = sc.next();
   if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   }
  
 } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   } S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3) S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3) S.charAt(0)==S.charAt(1) S.charAt(0) S.charAt S 0 S.charAt(1) S.charAt S 1 S.charAt(1)==S.charAt(2) S.charAt(1) S.charAt S 1 S.charAt(2) S.charAt S 2 S.charAt(2)==S.charAt(3) S.charAt(2) S.charAt S 2 S.charAt(3) S.charAt S 3 {
     System.out.println("No");
   } System.out.println("No") System.out.println System.out System System.out "No" if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   } S.charAt(0)==S.charAt(1) S.charAt(0) S.charAt S 0 S.charAt(1) S.charAt S 1 {
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   } if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     } S.charAt(2)==S.charAt(3) S.charAt(2) S.charAt S 2 S.charAt(3) S.charAt S 3 {
     System.out.println("Yes");
     } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
     System.out.println("No");
     } System.out.println("No") System.out.println System.out System System.out "No" if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   } S.charAt(0)==S.charAt(2) S.charAt(0) S.charAt S 0 S.charAt(2) S.charAt S 2 {
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   } if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     } S.charAt(1)==S.charAt(3) S.charAt(1) S.charAt S 1 S.charAt(3) S.charAt S 3 {
     System.out.println("Yes");
     } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
     System.out.println("No");
     } System.out.println("No") System.out.println System.out System System.out "No" if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   } S.charAt(0)==S.charAt(3) S.charAt(0) S.charAt S 0 S.charAt(3) S.charAt S 3 {
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   } if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     } S.charAt(1)==S.charAt(2) S.charAt(1) S.charAt S 1 S.charAt(2) S.charAt S 2 {
     System.out.println("Yes");
     } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
     System.out.println("No");
     } System.out.println("No") System.out.println System.out System System.out "No" if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   } S.charAt(1)==S.charAt(2) S.charAt(1) S.charAt S 1 S.charAt(2) S.charAt S 2 {
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   } if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     } S.charAt(0)==S.charAt(3) S.charAt(0) S.charAt S 0 S.charAt(3) S.charAt S 3 {
     System.out.println("Yes");
     } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
     System.out.println("No");
     } System.out.println("No") System.out.println System.out System System.out "No" if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   } S.charAt(1)==S.charAt(3) S.charAt(1) S.charAt S 1 S.charAt(3) S.charAt S 3 {
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   } if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     } S.charAt(0)==S.charAt(2) S.charAt(0) S.charAt S 0 S.charAt(2) S.charAt S 2 {
     System.out.println("Yes");
     } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
     System.out.println("No");
     } System.out.println("No") System.out.println System.out System System.out "No" if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   } S.charAt(2)==S.charAt(3) S.charAt(2) S.charAt S 2 S.charAt(3) S.charAt S 3 {
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   } if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     } S.charAt(0)==S.charAt(1) S.charAt(0) S.charAt S 0 S.charAt(1) S.charAt S 1 {
     System.out.println("Yes");
     } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
     System.out.println("No");
     } System.out.println("No") System.out.println System.out System System.out "No" {
     System.out.println("No");
   } System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main{
 public static void main(String[] args){
   Scanner sc = new Scanner(System.in);
   String S = sc.next();
   if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   }
  
 }
} public class Main{
 public static void main(String[] args){
   Scanner sc = new Scanner(System.in);
   String S = sc.next();
   if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   }
  
 }
} Main
import java.util.Scanner;
public class Main{
 public static void main(String[] args){
   Scanner sc = new Scanner(System.in);
   String S = sc.next();
   if(S.charAt(0)==S.charAt(1)&&S.charAt(1)==S.charAt(2)&&S.charAt(2)==S.charAt(3)){
     System.out.println("No");
   }else if(S.charAt(0)==S.charAt(1)){
     if(S.charAt(2)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(2)){
     if(S.charAt(1)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(0)==S.charAt(3)){
     if(S.charAt(1)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(2)){
     if(S.charAt(0)==S.charAt(3)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(1)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(2)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else if(S.charAt(2)==S.charAt(3)){
     if(S.charAt(0)==S.charAt(1)){
     System.out.println("Yes");
     }else{
     System.out.println("No");
     }
   }else{
     System.out.println("No");
   }
  
 }
}