Three. One to climb the ladder while the second kicks the ladder out from under her. And the third to say, "I knew that was too high for you dear."
or
Three, One to climb the ladder. One to shake it. And one to sue the ladder company.
or
Because they are black and white.
or
The price of bacon would go up.
or
Aye, Aye, Arr and the Seven C's
or