Lia is fascinated by anything she considers to be a twin. She calls a pairs of positive integers, and , twins if:

• They are both prime. A prime number is an integer greater than that has no positive divisors other than and itself.

• Their absolute difference is exactly equal to (i.e., ).

Given an inclusive interval of integers from to , can you help Lia find the number of pairs of twins there are in the interval (i.e., )? Note that pairs and are considered to be the same pair.