using System;
using System.Collections.Generic;
using System.Linq;

namespace yukicoder
{
	public class Program
	{
		public static void Main()
        {
			var g = Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray();
            var k = Knight();
            if (k.Any(value => value[0] == g[0] && value[1] == g[1]))
            {
                Console.WriteLine("YES");
            }
            else
            {
                Console.WriteLine("NO");
            }
        }
		public static List<int[]> Knight()
        {
			var k = new List<int[]>[4];
            var X = new int[2] { 2, -2 };
            var Y = new int[2] { 1, -1 };
            k[0]=new List<int[]>{ new int[2] { 0, 0 }};
            for (var i = 0; i < 3; i++)
            {
                k[i + 1] = new List<int[]>();
                foreach (var ks in k[i])
                {
                    foreach (var x in X)
                    {
                        foreach (var y in Y)
                        {
                            var a = ks[0] + x;
                            var b = ks[1] + y;
                            k[i + 1].Add(new int[2] { a, b });
                        }
                    }
                    foreach (var x in X)
                    {
                        foreach (var y in Y)
                        {
                            var a = ks[0] + y;
                            var b = ks[1] + x;
                            k[i + 1].Add(new int[2] { a, b });
                        }
                    }
                    k[i + 1] = k[i + 1].Distinct().ToList();
                }
            }
            var K = new List<int[]>();
            foreach(var ks in k)
            {
                K.AddRange(ks);
            }
            K = K.Distinct().ToList();
            return K;
        }
	}
}