Johnny and his friends have successfully moved on to the second room, where they meet the most terrifying thing of all: math!

Johnny flinched as soon as he saw the numbers. There were 3 of them, and Johnny didn't like a single one!

23
29
41

Well, maybe it wasn't that bad. Johnny also finds a scrap of paper with 2 words:

Product
Hexadecimal

Hexadecimal? Johnny has never heard of that word before.

He also finds a chest with a very odd lock. It has a 4-digit code, but the digits could either be a number or a letter from A to F...

Your job

Help Johnny and his friends open the chest! The chest must surely contain the key to escape!