namespace sdadsadadsdsadsa
{
internal class Program
{
static void Main(string[] args)
{
int a = Convert.ToInt32(Console.ReadLine());
double esayi = 1;
double fkt = 1;
for (int i = 0; i <= a; i++)
{
for (int j = 1; i <= a; j++)
{
fkt = j * fkt;
if (j == a)
{
esayi = esayi + (1 / fkt);
}
}
}
Console.WriteLine(esayi);
}
}
}