using System;								

    public class Boxing
    {
        static public void Main ()
        {
            double d = 5;
//  Pass a double to Square ()
            object o = Square (d);
            ShowSquare (o);
//  Pass an int to Square ()
            o = Square (10);
            ShowSquare (o);
//  Pass a float to Square ()
            o = Square (2.5F);
            ShowSquare (o);
        }

        static object Square (object o)
        {
            if (o is double)
                return ((double) o * (double) o);
            if (o is int)
                return ((int) o * (int) o);
            return (null);
        }

        static public void ShowSquare (object o)
        {
            if (Object.Equals (o, null))
                Console.WriteLine ("The object is null");
            else
                Console.WriteLine ("The square is " + o);
        }
    }