A bloke is walking down a country lane in Ireland when he sees a farmer coming towards him with a large sack over his shoulder.
"Morning there", he says "what would you be having in that there sack?"
"Pigs" says the Farmer
"If I were to guess how many pigs in that there sack would you give one them to me?" the man asks
The Farmer replies "If you can guess then I'll let you have the pair of them"
(Shameless lift from Sir Bernard of Manning)