Pichayoot Ouppaphan

My name is Pichayoot Ouppaphan, or you can called me Ob for short. I'm a sophomore in computer science, and I'm thinking about getting a minor in Mathematics. I'm from Thailand.

I am interested in prime number. The theorem I really like about prime number is Wilson's theorem, and it says
$p$ is a prime iff. $(p-1)! \equiv -1 \ (mod \ p).$