using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter a number");

        int num=int.Parse(Console.ReadLine());

        if (num>0 && num<10)

        {

            Console.WriteLine("Blue");

        }

        else if (num>10 && num<20)

        {

            Console.WriteLine("Red");

        }

        else if (num>20 && num<30)

        {

            Console.WriteLine("Green");

        }

        else 

        {

            Console.WriteLine("out of range");

        }

​

    }

}