CF113C Double Happiness

On the math lesson a teacher asked each pupil to come up with his own lucky numbers. As a fan of number theory Peter chose prime numbers. Bob was more original. He said that number $ t $ is his lucky number, if it can be represented as: $ t=a^{2}+b^{2}, $ where $ a,b $ are arbitrary positive integers.Now, the boys decided to find out how many days of the interval $ [l,r] $ ( $ l

The first line of the input contains integer numbers $ l,r $ ( $ 1

In the only line print the number of days on the segment $ [l,r] $ , which are lucky for Peter and Bob at the same time.