Two inexperienced hunters went hunting in the woods.  Before long, they got lost.

“Don’t worry,” said the first hunter.  “I heard that when you’re lost you should fire three shots in the air so somebody will hear you.”

They fired three shots in the air and waited.  A half hour later they tried it again and still no one came.  Finally they decided to try it a third time.

“This better work,” said the second hunter nervously.  “These’re our last arrows.”