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
    $lineNum = fgets(STDIN);

    $resultCount = 0;
    for ($i = 0; $i < $lineNum; $i++) {
        $val = (int)fgets(STDIN);
        if (isPrime($val)) {
            $resultCount++;
        }
    }

    echo $resultCount . PHP_EOL;

    function isPrime($num) {
        switch ($num) {
        case 1:
            return false;
        case 2:
            return true;
        }
        
        if ($num % 2 == 0) {
            return false;
        }

        $i = 0;
        for ($i = 2; $i * $i <= $num; $i++) {
            if ($num % $i == 0) {
                return false;
            }
        }
        return true;
    }