using System;

namespace yukicoder
{
    class Program
    {
        
        static void Main()
        {
            string[] s = Console.ReadLine().Split(' ');
            string[] t = Console.ReadLine().Split(' ');
            long K = long.Parse(s[1]);
            long C = 0;
            for (int i = 0; i < t.Length; i++)
            {
                if (long.Parse(t[i]) != i + 1) C++;
            }
            C /= 2;
            Console.WriteLine((K - C) % 2 == 0 ? "YES" : "NO");
            Console.ReadLine();
        }
    }

}