using System;

public class Program

{

    public static void Main()

    {

            string input;

            int inputNumber;

            int factorial = 1;

            int factorialSum = 0;

            int sequence;

            int firstNumber = 0;

            int secondNumber = 1;

​

            Console.WriteLine("Fibonacci Factorial");

            Console.Write("Enter a number: ");

            input = Console.ReadLine();

​

            if (Int32.TryParse(input, out inputNumber) == true)

            {

                if (inputNumber < 0)

                {

                    Console.WriteLine("0 or negative numbers are not allowed. ");

                }

                else

                {

                    Console.WriteLine("Sequence:");

                    Console.Write(firstNumber + " " + secondNumber + " "); //printing 0 and 1  

                    for (int i = 2; i <= inputNumber; ++i)

                    {

                        sequence = firstNumber + secondNumber;

                        Console.Write(sequence + " ");

                        firstNumber = secondNumber;

                        secondNumber = sequence;

                    }

                }

            }

    }

}