I couldn't AC this simple problem for a long time because I used seekeof! I always got WA 1. When I change my code and replace seekeof by reading symbol-by-symbol and use eof, I get AC. I think it was a bug in FreePascal because I use Delphi and my program with seekeof successfully works on my computer.
This is one more cause to replace FreePascal 2.0.4 by Delphi.

Yes! And because of the fact during the contest I spend too much time on this problem, and had only +4! This is obvious bug in Free Pascal compiler (or bad input files)