It's a duck that goes to a bar. He asks the Barman:
- Do you have milk?
- No, says the bartender.
The next day, the duck returns:
- Do you have milk?
- No, the bartender answers again.
On the third day, the duck returns again:
- Do you have milk?
- NO, impatient the Barman. There, if you come back to ask for milk, I nail you with a hammer.
- OK.
The next day, the duck returns:
- Do you have nails?
- No, said the Barman.
- Do you have a hammer?
- No.
- But can I have milk?