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
function isPrime( $x )
{
    if( 2 == $x ) return true;
    if( 0 == $x%2 ) return false;
    for( $i=3; $i*$i<=$x; $i++ ) {
        if( 0 == $x%$i ) { return false; }
    }
    return true;
}
	$n = trim( fgets( STDIN ) );
	$cnt = 0;
	$primes = [];
	while( $n-- ) {
		$num = trim( fgets( STDIN ) );
		if(  FALSE !== array_search( $num, $primes ) || isPrime( $num ) ) {
			array_push( $primes, $num );
			$primes = array_unique( $primes );
			$cnt++;
		}
	}
	print $cnt;
?>