Here is a link for the problem.

I found an approach in discussion: "You have to divide the participants into equal teams (rounded)", but I cannot understand why it's correct!

Hello everyone!

I'm solving the problem called "castle" from IOI'94. I solved it about 1.5 hour, and when I checked my solution with sample test and it was correct, I was so happy that finished debugging the code=) But when I submitted it I had signal #9. Please, tell me, what can it be?

Exact question: "What does signal #9 means?"

By the way, here is my code.

UPD: Thank you all for such silly opinions. If someone interested "what was it?", I've had memory limit.