
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        char[] S = scanner.next().toCharArray();

        if ((S[0] == S[1] && S[2] == S[3] && S[0] != S[2])
                || (S[0] == S[2] && S[1] == S[3] && S[0] != S[1])
                || (S[0] == S[3] && S[1] == S[2] && S[0] != S[1])) {
            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) {
        Scanner scanner = new Scanner(System.in);

        char[] S = scanner.next().toCharArray();

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

    }
} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        char[] S = scanner.next().toCharArray();

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

    } main {
        Scanner scanner = new Scanner(System.in);

        char[] S = scanner.next().toCharArray();

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

    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) char[] S = scanner.next().toCharArray(); S scanner.next().toCharArray() scanner.next().toCharArray scanner.next() scanner.next scanner if ((S[0] == S[1] && S[2] == S[3] && S[0] != S[2])
                || (S[0] == S[2] && S[1] == S[3] && S[0] != S[1])
                || (S[0] == S[3] && S[1] == S[2] && S[0] != S[1])) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        } (S[0] == S[1] && S[2] == S[3] && S[0] != S[2])
                || (S[0] == S[2] && S[1] == S[3] && S[0] != S[1])
                || (S[0] == S[3] && S[1] == S[2] && S[0] != S[1]) (S[0] == S[1] && S[2] == S[3] && S[0] != S[2])
                || (S[0] == S[2] && S[1] == S[3] && S[0] != S[1])
                || (S[0] == S[3] && S[1] == S[2] && S[0] != S[1]) (S[0] == S[1] && S[2] == S[3] && S[0] != S[2]) S[0] == S[1] && S[2] == S[3] && S[0] != S[2] S[0] == S[1] S[0] S 0 S[1] S 1 S[2] == S[3] S[2] S 2 S[3] S 3 S[0] != S[2] S[0] S 0 S[2] S 2 (S[0] == S[2] && S[1] == S[3] && S[0] != S[1]) S[0] == S[2] && S[1] == S[3] && S[0] != S[1] S[0] == S[2] S[0] S 0 S[2] S 2 S[1] == S[3] S[1] S 1 S[3] S 3 S[0] != S[1] S[0] S 0 S[1] S 1 (S[0] == S[3] && S[1] == S[2] && S[0] != S[1]) S[0] == S[3] && S[1] == S[2] && S[0] != S[1] S[0] == S[3] S[0] S 0 S[3] S 3 S[1] == S[2] S[1] S 1 S[2] S 2 S[0] != S[1] S[0] S 0 S[1] 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" String[] args args public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        char[] S = scanner.next().toCharArray();

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

    }
} public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        char[] S = scanner.next().toCharArray();

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

    }
} Main

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        char[] S = scanner.next().toCharArray();

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

    }
}
