Answer:
A Helen is a unit or measure of beauty named after the Helen of Troy from Homer's Iliad . In the book it is said that Helen's beauty set 1,186 ships to sail.
So, if someone says that (x) has 2 helens they mean that the person is so beautiful that 1,186 ships will set sail. There can be 2 helens for example so 2372 ships will set sail. There can also be negative helens so that ships sail AWAY from the person!
Hope it Helped!
P.S. There can be an infinite number of helens 1,2,3,4,...,112,etc.