using System;

using System.Numerics;

public class Program

{

    static BigInteger Factorial(int n)

    {

        BigInteger fact_n = 1;

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

        {

            fact_n *= i;

        }

        return fact_n;

    }

    public static void Main()

    {

        int n = int.Parse(Console.ReadLine());

        Console.WriteLine("Factorial of {0} is {1}.", n, Factorial(n));

    }

}

​

//Write a program that calculates and prints the n! for any n in the range

//[1…100].