How to submit in Pascal
Until Sep 8, 2002, we used gpc as Pascal compiler. Since then, we changed to FreePascal, which seems more useful. Please note that your program will be compiled with "-dONLINE_JUDGE -Sd" which defines the ONLINE_JUDGE according to the documentation you can find in this site, and also adjusts the data types and syntaxis to Delphi. Make sure you test your program with this directives in your machine before submitting!
As a side effect, FreePascal seems not to use signals to notify runtime errors, but emits a short text message which merges with your program outputs. So, if you have a runtime error, you will receive a Wrong Answer error instead. We know this is a problem, but we cannot focus on it right now.
There was a webpage in which we documented every problem we find about gpc. As we don't use gpc anymore, this document is not useful anymore. But, it is kept as documentation. You can find it here, but it will never be updated again.