Which number should replace the question mark?

One day the first grade teacher was reading the story of the Three Little Pigs to her class. She came to the part of the story where the first pig was trying to accumulate the building materials for his home. She read,"...and so the pig went up to the man with the wheel barrow full of straw and said, "Pardon me sir, but may I have some of that straw to build my house?"
The teacher paused then asked the class, "And what do you think that man said?"
One little boy raised his hand and said, "I think he said'Holy Sh*t! A talking pig!'"
The teacher was unable to teach for the next 10 minutes.