Problems
Count primes
Count primes
Given an integer interval [l, r] (0 ≤ l ≤ r ≤ 2147483647, r - l ≤ 106
), please calculate the number of primes in the interval.
Input
Two integer l and r.
Output
Print the number of primes in the interval.
Input example #1
2 11
Output example #1
5