using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter number to check whether it is prime or not:");

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

        int fact=factorial(num);

        Console.WriteLine("factorial of number is :" + fact);

    }

    static int factorial(int n){

        int f=1;

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

        f= f*i; 

    }

    return f;   

    }

}