Two dogs walk into a bar. The first dog says 'woof,' and the other dog says 'bark.' Now, tell me if you've heard this one before, two dogs walk into a bar. The first dog says 'woof,' and do you want to know what the other dog said? 'Bark.' Now, tell me if you've heard this one before. Two dogs walk into a bar. The first dog says to the second 'bark.' The second dog, in response, says 'bark.'