HackDalton: Decompile

Problem:

I found this program online, but I keep getting unlucky and not getting a flag. Can you help?

Name		Name	Last commit message	Last commit date
Latest commit History 5 Commits
.gitignore		.gitignore
CharShifter.java		CharShifter.java
Program.java		Program.java
README.md		README.md
WRITEUP.md		WRITEUP.md