6057: 区间质数个数

Memory Limit:128 MB Time Limit:1.000 S
Judge Style:Text Compare Creator:
Submit:26 Solved:32

Description

求区间[a,b]内质数的个数(1≤a,b≤5,000,000

Input

一行两个整数a,b

Output

一行一个整数表示答案

Sample Input Copy

22 33

Sample Output Copy

3