using System;

public class Program

{

    public static void Main()

    {

        int n= 123;

        int t = 0;

        while(n > 0)

        {

            int m = n%10;

            t = (t * 10) + m;

            n = n/10;

        }

        Console.WriteLine(t);

        var i=1;

        var temp1=1;

        var temp2=0;

        var temp3 = 0;

        /*for(var j = 1; j<= 20 ;j++)

        {

            temp = j;

            Console.WriteLine(temp);

            j = temp;

        }*/

        while(temp1<=20)

        {

            Console.WriteLine(temp1);

            temp2 = temp1; //1, 1, 2

            temp1 = temp2 + temp3; //1, 2, 3

            temp3 = temp2; //1, 1, 2

        }

    }

}