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;

class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int cnt=0;
		for(int i=0; i<N; i++){
			if(isPrime(sc.nextInt())) cnt++;
		}
		System.out.println(cnt);
	}
	static boolean isPrime(int x){
		int i, s;
		if(x==2){
			return true;
		}
		if(x<2 || x%2==0){
			return false;
		}
		i = 3;
		s = (int)Math.sqrt(x);
		while(i<=s){
			if(x%i==0){
				return false;
			}
			i += 2;
		}
		return true;
	}
}