A first grade teacher asks one of his pupils: "Brian, do you already know how to count?

Brian answers "Sure I do, my father taught me".

The teacher, who fails to believe little Bobby, decided to test the little guy. "OK, he continues Brian... what comes after two?" The teacher asks

"Three!" Brian instantly called out.

"Excellent" the teacher said, "OK, Brian, now, what comes after Five?"

"Six!" Brian said straight away

"Brian, I must say that your father is an outstanding teacher. I bet he is very proud of you"

"Oh, yes, he is" Brian replied

"OK, now for the last test"; the teacher said "What comes after ten?"

Bobby replied, without hesitating for a second "Jack"