import java.util.Scanner;

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

public class Main {
    public static void main(String args[]) {
        try (Scanner in = new Scanner(System.in)) {
            String s = in.next();
            if (s.charAt(0) == s.charAt(1)) {
                if (s.charAt(2)!=s.charAt(0) && s.charAt(2) == s.charAt(3)) {
                    System.out.println("Yes");
                    return;
                }
            } else if (s.charAt(0) == s.charAt(2)) {
                if (s.charAt(1)!=s.charAt(0) && s.charAt(1) == s.charAt(3)) {
                    System.out.println("Yes");
                    return;
                }
            } else if (s.charAt(0) == s.charAt(3)) {
                if (s.charAt(1)!=s.charAt(0) && s.charAt(1) == s.charAt(2)) {
                    System.out.println("Yes");
                    return;
                }
            }
            System.out.println("No");
        }
    }
}
