import java.util.Scanner;
public class Main{
	public static void main(String[]args){
    Scanner sc=new Scanner(System.in);
      String S=sc.next();
      char m0=S.charAt(0);
      char m1=S.charAt(1);
      char m2=S.charAt(2);
      char m3=S.charAt(3);
      if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	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();
      char m0=S.charAt(0);
      char m1=S.charAt(1);
      char m2=S.charAt(2);
      char m3=S.charAt(3);
      if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	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();
      char m0=S.charAt(0);
      char m1=S.charAt(1);
      char m2=S.charAt(2);
      char m3=S.charAt(3);
      if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	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();
      char m0=S.charAt(0);
      char m1=S.charAt(1);
      char m2=S.charAt(2);
      char m3=S.charAt(3);
      if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	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 char m0=S.charAt(0); m0 S.charAt(0) S.charAt S 0 char m1=S.charAt(1); m1 S.charAt(1) S.charAt S 1 char m2=S.charAt(2); m2 S.charAt(2) S.charAt S 2 char m3=S.charAt(3); m3 S.charAt(3) S.charAt S 3 if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else{
      	System.out.println("No");
      } m0==m1 m0 m1 {
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      } if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        } m2==m3 m2 m3 {
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        } if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            } m0==m2 m0 m2 {
            	System.out.println("No");
            } System.out.println("No") System.out.println System.out System System.out "No" {
            	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(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else{
      	System.out.println("No");
      } m0==m2 m0 m2 {
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      } if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        } m1==m3 m1 m3 {
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        } if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            } m0==m1 m0 m1 {
            	System.out.println("No");
            } System.out.println("No") System.out.println System.out System System.out "No" {
            	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(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else{
      	System.out.println("No");
      } m0==m3 m0 m3 {
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      } if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        } m1==m2 m1 m2 {
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        } if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            } m0==m1 m0 m1 {
            	System.out.println("No");
            } System.out.println("No") System.out.println System.out System System.out "No" {
            	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();
      char m0=S.charAt(0);
      char m1=S.charAt(1);
      char m2=S.charAt(2);
      char m3=S.charAt(3);
      if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	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();
      char m0=S.charAt(0);
      char m1=S.charAt(1);
      char m2=S.charAt(2);
      char m3=S.charAt(3);
      if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	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();
      char m0=S.charAt(0);
      char m1=S.charAt(1);
      char m2=S.charAt(2);
      char m3=S.charAt(3);
      if(m0==m1){
      	if(m2==m3){
        	if(m0==m2){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m2){
      	if(m1==m3){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else if(m0==m3){
      	if(m1==m2){
        	if(m0==m1){
            	System.out.println("No");
            }else{
            	System.out.println("Yes");
            }
        }
        else{
        	System.out.println("No");
        }
      }else{
      	System.out.println("No");
      }
    }
}