using System.Numerics;

public class Program
{
    public static void Main()
    {
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        string str = Console.ReadLine() ?? string.Empty;



        if(str.Length == 2)
        {
            Console.WriteLine("Yes");
        }
        else
        {
            Console.WriteLine("No");
        }


    }
}