Primes in Interval
Description
You are given two integers a and b (a ≤ b). How many prime numbers are there on the interval from a to b, inclusive?
The input contains two integers a and b (2 ≤ a ≤ b ≤ 1 000 000), separated by a single space.
Output a single integer — the number of primes between a and b, inclusive.
Input
The input contains two integers a and b (2 ≤ a ≤ b ≤ 1 000 000), separated by a single space.
Output
Output a single integer — the number of primes between a and b, inclusive.
Samples
10 20
4
23 23
1
271 566
46