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;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace _001_FindingMissingCards
{


    class Program
    {
        static Boolean primeNumber(int x)
        {
            if (x == 2) return true;
            if (x % 2 == 0 || x < 2) return false;

            var i = 3;
            while (i <= Convert.ToInt32(Math.Sqrt(Convert.ToDouble(x))))
            {
                if (x % i == 0) return false;
                i += 2;
            }

            return true;
        }
        static void Main()
        {
            var num = Convert.ToInt32(Console.ReadLine());

            var count = 0;

            for (int i = 0; i < num; i++)
            {
                var x = Convert.ToInt32(Console.ReadLine());
                if (Program.primeNumber(x))
                {
                    count++;
                }
            }
            Console.WriteLine(count);
            
        }
    }
}