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.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

class Main{

	public static void main(String[] args) throws IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		int[] x = new int[n];
		int count = 0;

		for(int i = 0; i < n; i++){
			x[i] = Integer.parseInt(br.readLine());
		}

		for(int i = 0; i < n; i++){
			
			if(isPrime(x[i])){
				count++;
			}

		}

		System.out.println(count);

	}

	static boolean isPrime(int x){

		if(x == 2){
			return true;
		}

		if(x < 2 || (x % 2) == 0){
			return false;
		}

		int i = 3;

		while(i <= Math.sqrt(x)){

			if((x % i) == 0){
				return false;
			}

			i += 2;

		}

		return true;

	}

}