Mastering Nim contest winners

The contest is over! A gold crown can be seen by turning the picture upside down:

We received lots of correct answers! Among those who answered correctly, three lucky winners were chosen by random draw.

An email has been sent to the lucky winners and we hope they reply in time with their postal addresses so that they can receive their signed books before Christmas eve. Due to privacy concerns we will not publish any information about the winners. If they want, they can share the information on our forum.

We thank everybody who has participated and wish you a happy Santa Claus!