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 PHP (judge verdict: Accepted)

<?php
$count = trim(fgets(STDIN));
$out = 0;
for ($i = 0; $i < $count; $i++) {
    $n = trim(fgets(STDIN));
	$out = $out + isprime($n);
}
	print($out);
function isprime($n) {
	if ($n == 2) {
		return 1;
	} else if ($n % 2 == 0) {
		return 0;
	} else {
		for ($i = 3; sqrt($n) >= $i; $i+=2) {
			if ($n % $i == 0) {
				return 0;
				break;
			}
		}
		return 1;
	}
}
?>