How to count the number of visitors to an event using improvised means?

Question

Analytics

Hello, gentlemen Connoisseurs!
I'm organizing an offline event in my city, and I set out to find a relatively cheap (or better - free, non-commercial activity) way to count the total number of unique visitors. By the way, the event is small, up to a thousand people, but it is necessary to conduct an accurate analysis.
For obvious reasons, the option “to put a girl with a counter in her hands for two days of the event” will not work.
I know that there are firms, and they have special tools for directly dealing with the subject, but this option strongly rests on the financial side of the issue, the problems with which are described above.
To record on a webcam all the people passing into the hall, and then sit and count for several nights in a row is a dreary and thankless task. But maybe there is some software, or some other methods unknown to me, to automate this process? Perhaps there are other solutions?
Many thanks in advance for your help!

Answer 1

What nonsense, to hire a girl for two days with a mechanical counter costs a thousand rubles.
Raising a full-fledged recognition and accounting system costs thousands of dollars.
If you have money, it's not a question to contact a company that deals with this, if there is no money, buy a mechanical counter and let the girl work.
I have always been surprised by the desire of IT people to use tools for other purposes.