using System;

public class Program

{

    public static void Multiply(ref int x, int y)

    {

        x = x * y;

    }

    public static void Main()

    {

        Console.WriteLine("Let's do some math!");

        Console.WriteLine("Enter in a number");

        int input = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("What number should be multiply it by?");

        int choice = Convert.ToInt32(Console.ReadLine());

        int refx = input;

        Multiply (ref input, choice);

        Console.WriteLine("{0} * {1} = {2}", refx, choice, input);

    }

}