Last Tuesday, we announced Cemetech Contest #15: Crypto Golfing. This five-part contest tasks programmers with solving cryptography puzzles, then creating programs that can decode messages in the cipher used for each challenge. We received an overwhelming number of entries written in many different calculator and computer languages for Challenge 1. Since another Tuesday is upon us, Challenge 2 of Cemetech Contest #15 is also here! If you haven't completed Challenge 1 yet, you still have time, and the only thing you'll lose is the (up to) 5 bonus points you get by submitting your solutions quickly. Challenge 2 adds a few additional rules that we learned from seeing how people worked with Challenge 1:
For Challenges 2 and 3, TI-BASIC, Axe, and Assembly programs should take the ciphertext in Ans and return the decoded plaintext in Ans as well.
For Challenges 2 and 3, computer programs should take input from stdin and return output to stdout.
If there are any constants or keys that affect how a particular cipher works (for example, the offset in a Caesar cipher), these should be defined in a modifiable way in the source, so that someone with the source code could change those constants without needing to modify anything else in the program.