[RC3-2017 CTF] Science Class

Writeup by Ninjailbreak

The Mission:
This is going to be a great year!
Barely five minutes into chemistry and your friend passes you this note inviting you to a party!
What do they want you to bring?

We easily can recognize the “Periodic Table” in the PDF file, so we combine the table with the PDF and got a list of elements

Periodic Table

Be, S, Ga, Se, Er.

after some combinations we guess the string “BeErGaSeS”
changing the cases and submit the flag
>> RC3-2017{BeerGases} <<