C# 


class Result
{
//i change this method to void and ref result instead of return as
//there is an issue with ascii bla3

    public static void factorial(int n, ref int result)
    {
        for (Int32 i = n; i > 0; i--)
        {
            result *= i;
        }
    }
}

class Solution
{
    public static void Main(string[] args)
    {
        Int32 n = Convert.ToInt32(Console.ReadLine());

        Int32 result = 1;
        
        Result.factorial(n,ref result);

        Console.WriteLine(result);
    }
}