using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

{

    partial class Arithmetic

    {

        public int Factorial(int num)

        {

            int factorial = 1;

            for (int i = num; i > 0; i--)

            {

                factorial *= i;

            }

            return factorial;

        }

    }

    partial class Arithmetic

    {

        public int Square(int num)

        {

            return num * num;

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            Arithmetic a = new Arithmetic();

            int num = 5;

            Console.WriteLine("求 {0} 的阶乘：",num);

            Console.WriteLine(a.Factorial(num));

            Console.WriteLine("求 {0} 的平方：", num);

            Console.WriteLine(a.Square(num));

            Console.ReadKey();

        }

    }

}