A duck walks into a store and asks the cashier, "Do you have any grapes?"

The cashier says, "Sorry, we don't sell grapes here."

The next day, the duck comes back and asks the same question, "Do you have any grapes?"

The cashier, a little confused, says, "I told you yesterday, we don't sell grapes."

The duck leaves.

This keeps happening for the next few days, until finally, the cashier says, "Listen, if you come back here asking for grapes one more time, I'm going to nail your beak to the floor!"

The next day, the duck walks in and asks, "Do you have any nails?"

The cashier replies, "No, we don't have any nails."

"Do you have any grapes?" the duck asks