//BELECINA, RHENIEL JACOB M.

//CCP 1103 - ITBC

//FIBONACCI FREEZE

​

using System;

public class Program

{

    public static void Main()

    {

            int inputNumber;

            int counter = 0;

            int previousNumber = 0;

            int nextNumber = 1;

            string number;

​

            Console.WriteLine("Fibonacci Freeze"); 

            Console.WriteLine();

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

            number = Console.ReadLine();

​

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

            {

                if (inputNumber < 1)

                {

                    Console.WriteLine("Zero or negative input is not allowed.");

                }

                else if (inputNumber > 50)

                {

                    Console.WriteLine("Invalid input. Only one to fifty is allowed");

                }

                else

                {

                    for (int anotherNumber = 1; anotherNumber < inputNumber; anotherNumber++)

                    {

                        counter = previousNumber + nextNumber;

                        previousNumber = nextNumber;

                        nextNumber = counter;

                    }

                    Console.WriteLine("The fibonacci number for {0:#,0.00}", inputNumber + " is " + counter + ".");

                }

            }

            else

            {

                Console.WriteLine("Invalid input. Please enter a numeric value.");

            }

    }

}