A mind-bending coffee riddle is breaking the internet, or at least, brewing it.
The riddle was posted on Twitter in early November and has been puzzling users since.
It shows a carafe pouring coffee into a network of pipes that lead to four cups. The question is simple: Which cup will get coffee first?
The answer may not be so simple. In fact, it has left Twitter users percolating with debate.
Care to venture a guess?
You may want to brew some coffee because you may be here a while.