Fibonacci

using System;

class Fibonacci
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());

        if (n <= 1)
        {
            Console.WriteLine(0);
        }
        else
        {
            int firstNumber = 0;
            int secondNumber = 1;
            int sum = firstNumber + secondNumber;
            Console.Write("{0}, {1}",firstNumber, secondNumber);
            for (int i = 0; i < n - 2; i++)
            {
                sum = firstNumber + secondNumber;
                firstNumber = secondNumber;
                secondNumber = sum;
                Console.Write(", {0}" , sum);
            }
        }

    }
}