They each take a sack, and go their separate ways.
After awhile they meet again and one asks the other, "What did you find in your sack?"
"Five hundred thousand pounds," he says.
"Wow... that's a lot! What did you do with the cash?"
"I bought a house. How about your sack?"
"Oh, it was full of bills."
"And what did you do with them?"
Spoiler: