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 C# (judge verdict: Accepted)

using System;

public class Test
{
	public static void Main( )
	{
		int n = int.Parse( Console.ReadLine() );
		int[] nums = new int[n+1];
		for( var i=0; i<n; i++ ) {
			nums[i] = int.Parse( Console.ReadLine() );
		}
	
		int cnt = n;
		for( var i=0; i<n; i++ ) {
			if( 2 == nums[i] || 3 == nums[i] ) { continue; }
			if( 0 == nums[i]%2 ) {
				cnt--;
				continue;
			}

			for( var j=3; j<=Math.Sqrt( nums[i] ); j+=2 ) {
				if( 0 == nums[i]%j ) {
					cnt--;
					break;
				}
			}
		}
		
		Console.WriteLine( cnt );
	}
}