Numbers

All the numbers went to a party and numbers being what they are, all
the evens stayed around each other and all the odds did the same and
neither group interacted with each other. Whilst two was chatting to
four he noticed zero was on his own in the corner and suggested to
four that because zero is sort of even he should be encouraged to mix
with even numbers - four agreed. So off went two to invite zero into
their little group. "Would you like to join our little group" enquired
two, to which zero replied "I have nothing to add!"