To recover the paradoxical result that entropy is not extensive, we integrate over phase space for a gas of n monatomic particles confined to a single spatial dimension by 0 < x < ℓ ℓ . Since our only purpose is to illuminate a paradox, we simplify notation by taking the particle's mass and the Boltzmann constant equal to unity: m = k = 1 . We represent points in phase-space and its x and v parts by n and 2 n dimensional vectors: