public static void Main()
Console.WriteLine("Please enter a number to calculate the factorial of");
ulong fact = ulong.Parse(Console.ReadLine());
for(ulong i = 1; i > 0; i++)
Console.WriteLine("The factorial of " + fact + " is ");
Console.WriteLine("Would you like to run the program again? y/n");
string choice = Console.ReadLine();
if (choice == "y" || choice == "Y")