class Program
{
    static int[][] list = {
        new int[] { 1 },
        new int[] { 8, 4 },
        new int[] { 2, 6, 9 },
        new int[] { 8, 5, 9, 3 }
    };

    static bool IsPrime(int num)
    {
        if (num < 2)
            return false;
        for (int i = 2; i * i <= num; i++)
        {
            if (num % i == 0)
                return false;
        }
        return true;
    }

    static void Main(string[] args)
    {
        int rowCount = list.Length;

        for (int i = rowCount - 2; i >= 0; i--)
        {
            for (int j = 0; j <= i; j++)
            {
                if (!IsPrime(list[i][j]))
                {
                    list[i][j] += Math.Max(list[i + 1][j], list[i + 1][j + 1]);
                }
            }
        }

        int totalMax = list[0][0];
        Console.WriteLine("Sum: " + totalMax);
    }
}