On a narrow mountain's road a man saw a police car driving uphill backwards.
- Hi guys.
Why are you driving backwards?
- Because we are not sure that we will find the place to make u-turn on the top of the mountain.
After one hour the same man saw the same police car driving downhill backwards again.
- But guys, why are you driving backwards again?
- We have found the place to make u-turn up there.