Na'an

Difficulty:
Direct link: Objective URL

Objective

Request

Shifty McShuffles is hustling cards on Film Noir Island. Outwit that meddling elf and win!

Shifty McShuffles

Copy the first part of the conversation with Elf Name here Hey there, stranger! Fancy a game of cards? Luck's on your side today, I can feel it.
Step right up, test your wit! These cards could be your ticket to fortune.
Trust me, I've got a good eye for winners, and you've got the look of luck about you.
Plus, I'd wager you've never played this game before, as this isn't any ordinary deck of cards. It's made with Python.
The name of the game is to bamboozle the dealer.
So whad'ya think? Are you clever enough?

Hints

Stump the Chump

Try to outsmart Shifty by sending him an error he may not understand.

The Upper Hand

Shifty said his deck of cards is made with Python. Surely there's a weakness to give you the upper hand in his game.

Solution

First we found information application is written in Python.

After inserting NAN value into the middle card we confused game and won!

https://discuss.python.org/t/nan-breaks-min-max-and-sorting-functions-a-solution/2868

Python isn’t “type safe”, it’s “duck typed”. It's not IEEE754 compliant.

The good news: easily fixable by a competent dev on a case-by-case basis (like any injection attack mitigation) using isnan() wisely and most likely failure modes are going to be logic flaws or ValueError crashes. Bad news: it's VERY dangerous to test in prod.

Answer

NAN

Response

Shifty McShuffles

Well, you sure are more clever than most of the tourists that show up here.