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;

class Program
{
	static void Main(string[] args)
	{
		int n = int.Parse(Console.ReadLine());

		int count = 0;
		for (int i = 0; i < n; i++)
		{
			int a = int.Parse(Console.ReadLine());

			if (IsPrime(a))
			{
				count ++;
			}
		}

		Console.WriteLine(count);
	}

	static bool IsPrime(int n)
	{
		int p = (int)Math.Sqrt(n);

		for (int i = 2; i <= p; i += (i ==2) ? 1 : 2)
		{
			if (n % i == 0)
			{
				return false;
			}
		}
		return true;
	}
}