Two's in - there's also a clever algorithm that is based on the nocturnal micturation frequency of the forum's posters
Its a bit more complicated, involving intake between noon and bed, the sum of the several nocturnal dribbles in metric, the number of visits, the number of visits whereby bedfellow is disturbed and the phase of the moon [tides, you see].
And you thought DRE was Defence of the Realm Act Exemptions?