Today my friend told me that my solution for problem D in yesterday's educational contest failed on system tests. "Another silly bug", I thought.

I opened my submissions to check why it failed and I was surprised to see that the verdict was compilation error!

This is my submission, and this is what the error message says:

Can't compile file: Compilation process returned error: idleness limit exceeded (process hangs)

Any idea why this could happen? It's unrated anyways so it's not a big deal but this may have happened to other rated participants too.