Snakes are laid out on a plane with the following requirements:
- Each snake has 3 parts: head, middle and tail.
- Each snake is touched by exactly one head, one middle, and one tail.
- Each snake can only touch another snake at most once.
- Each part of a snake must touch a different part of another snake (no
head-head, middle-middle, tail-tail).
- The snakes can’t overlap or cross as they are on a plane.
What is the minimum number of snakes that you need?