Test Numbers

            int N = int.Parse(Console.ReadLine());
            int M = int.Parse(Console.ReadLine());
            int maxSum = int.Parse(Console.ReadLine());

            int sum = 0;
            int counter = 0;

            for (int i = N; i >= 1; i--)
            {
                for (int j = 1; j <= M; j++)
                {
                    sum += 3 * i * j;
                    counter++;

                    if (sum >= maxSum)
                    {
                        Console.WriteLine($"{counter} combinations");
                        Console.WriteLine($"Sum: {sum} >= {maxSum}");
                        return;
                    }
                }
            }

            Console.WriteLine($"{counter} combinations");
            Console.WriteLine($"Sum: {sum}");