using System;
public class Program
{
public static void Main()
Console.WriteLine("Votre nombre ?");
int n = Convert .ToInt32 (Console.ReadLine() ) ;
int m = 1;
if (n >= 1)
while (n > 0)
m = m * n;
n = n - 1;
}
Console.WriteLine("Factorielle:" + m);
} else {
Console.WriteLine("Impossible");