Question
Counting Primes Between Two Numbers
You are given two integers KaTeX can only parse string typed expression and KaTeX can only parse string typed expression. Your task is to count how many prime numbers lie in the range KaTeX can only parse string typed expression, both inclusive.
A prime number is a number greater than 1 that has exactly two distinct positive divisors: 1 and itself.
Input
The first line contains two integers KaTeX can only parse string typed expression and KaTeX can only parse string typed expression, representing the range.
Output
Print a single integer — the number of prime numbers in the range KaTeX can only parse string typed expression.
Example
Input
10 20
Output
4
Explanation
The numbers in the range KaTeX can only parse string typed expression are:
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20
The prime numbers among them are:
11, 13, 17, 19
Total = 4 prime numbers.
10 20
Output
4
Explanation
The numbers in the range KaTeX can only parse string typed expression are:
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20
The prime numbers among them are:
11, 13, 17, 19
Total = 4 prime numbers.