class Program
{
    static void Main(string[] args)
    {
        string[] input = Console.ReadLine()!.Split(' ');
        int man = int.Parse(input[0]);
        int woman = int.Parse(input[1]);

        int ans = (man + 1) - woman;
        if (ans != 0)
        {
            Console.WriteLine("NO");
            Console.WriteLine(ans);
        }
        else
        {
            Console.WriteLine("YES");
            Console.WriteLine(ans);
        }
    }
}