Stealing a Bus

 Paddy and Mick are walking home after a night on the piss.
 They've got no money to get a taxi and are staggering all over
 the place when they find themselves outside the bus depot.  Paddy has
 a brainwave and says to Mick  "Get in there and steal a bus so we can
 drive home and I'll stay out here and look out for the police". Mick
 duly breaks into the garage and is gone for twenty minutes while Paddy
 is wondering what the hell he's doing. Eventually Paddy sticks his
 head around the door and sees Mick running from bus to bus and looking
 very worried.

 "What the hell are you doing Mick, get a move on!"  to which
 Mick replies "I can't find a number 7 anywhere Paddy"  whereupon
 Paddy, holding his hands to his head in disbelief, shouts "You fucking
 idiot Mick, steal a number 9 and we'll get off at the roundabout and
 walk the rest of the way!".