import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final String s = sc.next();
        final char[] c = s.toCharArray();

        if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final String s = sc.next();
        final char[] c = s.toCharArray();

        if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} Main public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final String s = sc.next();
        final char[] c = s.toCharArray();

        if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    } main {
        final Scanner sc = new Scanner(System.in);

        final String s = sc.next();
        final char[] c = s.toCharArray();

        if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    } final Scanner sc = new Scanner(System.in); sc new Scanner(System.in) final String s = sc.next(); s sc.next() sc.next sc final char[] c = s.toCharArray(); c s.toCharArray() s.toCharArray s if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        } (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2]) (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2]) (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3]) c[0] != c[3] c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3] c[0] == c[1] c[0] c 0 c[1] c 1 c[0] != c[2] c[0] c 0 c[2] c 2 c[0] != c[3] c[0] c 0 c[3] c 3 c[2] == c[3] c[2] c 2 c[3] c 3 (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3]) c[0] != c[3] c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3] c[0] == c[2] c[0] c 0 c[2] c 2 c[0] != c[1] c[0] c 0 c[1] c 1 c[0] != c[3] c[0] c 0 c[3] c 3 c[1] == c[3] c[1] c 1 c[3] c 3 (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2]) c[0] != c[2] c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2] c[0] == c[3] c[0] c 0 c[3] c 3 c[0] != c[1] c[0] c 0 c[1] c 1 c[0] != c[2] c[0] c 0 c[2] c 2 c[1] == c[2] c[1] c 1 c[2] c 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" String[] args args public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final String s = sc.next();
        final char[] c = s.toCharArray();

        if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final String s = sc.next();
        final char[] c = s.toCharArray();

        if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final String s = sc.next();
        final char[] c = s.toCharArray();

        if (   (c[0] == c[1] && c[0] != c[2] && c[0] != c[3] && c[2] == c[3])
            || (c[0] == c[2] && c[0] != c[1] && c[0] != c[3] && c[1] == c[3])
            || (c[0] == c[3] && c[0] != c[1] && c[0] != c[2] && c[1] == c[2])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
}
