There are two kinds of mathematicians: those who can count and those who can't. There are two groups of people in the world; those who believe that the world can be divided into two groups of people, and those who don't. There are two groups of people in the world: Those who can be categorized into one of two groups of people, and those who can't.

• 1
• 2
• 3
• 4
• 5