ELO

 static void Main(string[] args)
        {


            int[] tab = {1, 8, 1, 1, 5, 7, 1, 1};
            int count = 1, max = 0;
            for (int i = 0; i < tab.Length; i++)
            {
                if ((i + 1) < tab.Length && tab[i] <= tab[i + 1])
                    count++;
                else
                {
                    if (max < count)
                        max = count;
                    count = 1;
                }
            }
            Console.WriteLine(max);
            Console.ReadKey();
        }