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 $[l,r]$ ( $l<=r$ ) are suitable for pair programming. They decided that the day $i$ ( $l<=i<=r$ ) is suitable for pair programming if and only if the number $i$ is lucky for Peter and lucky for Bob at the same time. Help the boys to find the number of such days.

The first line of the input contains integer numbers $l,r$ ( $1<=l,r<=3·10^{8}$ ).

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.