5 shy dudes who can never talk for themselves stand in a circle.
Every time you ask one of them a question, the dude to their right will answer for them.
3 of them always lie and 2 of them always tell the truth.
The dudes are all-knowing about each other.
How many yes/no questions will it take you to find the 3 liars?
NOTE
The answers you receive are always formulated as such : "He wants to say [yes/no]".