Problem:
Prime Numbers

A prime number is a natural number which has exactly two distinct natural number divisors: 1 and itself. For example, the first four prime numbers are: 2, 3, 5 and 7.

Write a program which reads a list of N integers and prints the number of prime numbers in the list.

Input

The first line contains an integer N, the number of elements in the list.

N numbers are given in the following lines.

Output

Print the number of prime numbers in the given list.

Constraints

1 ≤ N ≤ 10000

2 ≤ an element of the list ≤ 108

Sample Input 1

5
2
3
4
5
6

Sample Output 1

3

Sample Input 2

11
7
8
9
10
11
12
13
14
15
16
17

Sample Output 2

4

Solution in JAVA (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
	public static void main(String[] wjy) {
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int k=0;
		//ArrayList<Integer> tar = new ArrayList<Integer>();
		for (int i= 0;i<num;i++) {
			int aim = sc.nextInt();
			if (Pri(aim)) {
				//tar.add(aim);
				k++;
			}
		}
		//System.out.println(tar);
		System.out.println(k);
	}
	public static boolean Pri(int a) {
		if (a<=3) {
			return a>1;
		}
		else {
			if (a%2==0) {
				return false;
			}
		    if (a%3==0) {
		    	return false;
		    }
		    int k =5;
		    while ((k*k)<=a) {
		    	if (a% k == 0) {
		    		return false;
		    	}
		    	else if (a%(k+2)==0) {
		    		return false;
		    	}
		    	k=k+6;
		    }
		    return true;
		}
	}
}