How many prime numbers

Problem Description
Give you a lot of positive integers, just to find out how many prime numbers there are.

Input
There are a lot of cases. In each case, there is an integer N representing the number of integers to find. Each integer won’t exceed 32-bit signed integer, and each of them won’t be less than 2.

Output
For each case, print the number of prime numbers you have found out.

Sample Input
3
2 3 4

Sample Output
2

http://www.cnblogs.com/Su-Blog/archive/2012/08/27/2659145.html