using System;

public class Program

{

    public static void Main()

    {

        int i,n;

        Console.WriteLine("Test Data :");

        Console.WriteLine("Input the number :");

        n=Convert.ToInt32(Console.ReadLine());

                          Console.WriteLine("The Factorial of {0} is: ",n); 

        int x =1;

        for(i=1;i<=n;i++)

        {

            x *= i;

        }

        Console.Write(x);

    }

    }

​