#nullable enable

#region
var (_input, _iter) = (Array.Empty<string>(), 0);
T I<T>() where T : IParsable<T>
{
    while (_iter >= _input.Length) (_input, _iter) = (Console.ReadLine()!.Trim().Split(' '), 0);
    return T.Parse(_input[_iter++], null);
}
#endregion

var c1 = I<string>()[0] - 'A';
var c2 = I<string>()[0] - 'A';
var ans = Math.Abs(c1 - c2) == 1;
Console.WriteLine(ans ? "Yes" : "No");