Now that this thread has been moved to the Europe forum I suggest you scroll down about half a dozen threads to the one about "been in Schengen too long" where (towards the end of the thread) you will find someone's report of what happened when they overstayed.

This is Europe. You are unlikely to end up in prison (as some people seem to think). You will just get fined and deported and barred from re-entering. Your passport will almost definitely have been scanned on the way in (they can scan passports while, seemingly, just looking at them) so you WILL get caught - don't be under any illusions.

If you have a legitimate reason for staying longer then, as suggested previously, try to get a visa. If you don't have a legitimate reason then you don't stand a chance.

And please don't expect people here to give you advice on how to break the law.