import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        Scanner hi = new Scanner(System.in);
        String S = hi.nextLine();

        char g = S.charAt(0);
        if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                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 hi = new Scanner(System.in);
        String S = hi.nextLine();

        char g = S.charAt(0);
        if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                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 hi = new Scanner(System.in);
        String S = hi.nextLine();

        char g = S.charAt(0);
        if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }

        else System.out.println("No");
    } main {
        Scanner hi = new Scanner(System.in);
        String S = hi.nextLine();

        char g = S.charAt(0);
        if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }

        else System.out.println("No");
    } Scanner hi = new Scanner(System.in); hi new Scanner(System.in) String S = hi.nextLine(); S hi.nextLine() hi.nextLine hi char g = S.charAt(0); g S.charAt(0) S.charAt S 0 if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                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 {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } char r = S.charAt(2); r S.charAt(2) S.charAt S 2 if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != 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 {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            } if (S.charAt(0) == S.charAt(3))
                    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("No") System.out.println System.out System System.out "No" if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes"); 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 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)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                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 {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        } char r = S.charAt(2); r S.charAt(2) S.charAt S 2 if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    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 {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            } if (S.charAt(0) == S.charAt(1))
                    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("No") System.out.println System.out System System.out "No" if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes"); 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 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))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                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 {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        } char r = S.charAt(2); r S.charAt(2) S.charAt S 2 if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    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 {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            } if (S.charAt(0) == S.charAt(1))
                    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("No") System.out.println System.out System System.out "No" if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes"); 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 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 System.out System System.out "No" String[] args args public class Main {

    public static void main(String[] args) {
        Scanner hi = new Scanner(System.in);
        String S = hi.nextLine();

        char g = S.charAt(0);
        if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                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 hi = new Scanner(System.in);
        String S = hi.nextLine();

        char g = S.charAt(0);
        if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                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 hi = new Scanner(System.in);
        String S = hi.nextLine();

        char g = S.charAt(0);
        if (S.charAt(0) == S.charAt(1)) {

            char r = S.charAt(2);
            if (S.charAt(2) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(3))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(3))
                    System.out.println("Yes");
            }
                 else{
                    System.out.println("No");
            }
        } else if (S.charAt(0) == S.charAt(2)) {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(3))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }else if (S.charAt(0) == S.charAt(3))
        {
            char r = S.charAt(2);
            if (S.charAt(1) == S.charAt(2))
            {
                if (S.charAt(0) == S.charAt(1))
                    System.out.println("No");
                if (S.charAt(0) != S.charAt(1))
                    System.out.println("Yes");
            }
            else{
                System.out.println("No");
            }


        }

        else System.out.println("No");
    }


}
