Challenge description
Can you get the flag? Reverse engineer this Java program.
Category: Reverse Engineering
Solution
As the challenge suggested, I threw the provided program at an online Java decomplier. I used this one.

You can make out the flag by looking at each character the program checks for, from the bottom up.
The re-assembled flag reads: picoCTF{700l1ng_r3qu1r3d_84e23997}