27.12-02.TribonacciTriangle

using System;

class TribonacciTriangle
{
    static void Main()
    {
        long first = long.Parse(Console.ReadLine());
        long second = long.Parse(Console.ReadLine());
        long third = long.Parse(Console.ReadLine());

        byte L = byte.Parse(Console.ReadLine());

        for (int i = 0; i < L; i++)
        {
            for (int j = 0; j <= i; j++)
            {
                long newNum = first + second + third;

                if (j > 0)
                {
                    Console.Write(' ');
                }

                Console.Write(first);

                first = second;
                second = third;
                third = newNum;
            }

            Console.WriteLine();
        }
    }
}