Well, the answer is four

Little Johnny was sitting in class doing math problems when his teacher picked him to answer a question, "Johnny, if there were five birds sitting on a fence and you shot one with your gun, how many would be left?" "None," replied Johnny, "cause the rest would fly away." "Well, the answer is four," said the teacher, "but I like the way you're thinking."

Little Johnny says, "I have a question for you. If there were three women eating ice cream cones in a shop, one was licking her cone, the second was biting her cone and the third was sucking her cone, which one is married?"

"Well," said the teacher nervously, "I guess the one sucking the cone."

"No," said Little Johnny, "the one with the wedding ring on her finger, but I like the way you're thinking."