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 ConsoleApplication33
{
    class Program
    {
        static bool PrimeNumbers(int a)
        {
            if (a == 2) return true;
            for(int b=2; ; b++)
            {
                if (a % b == 0) return false;
                if ((b + 1) * (b + 1) > a) return true;
            }
        }


        static void Main()
        {
            int s = 0;
            int a = int.Parse(Console.ReadLine());
            for(int b = 0; b < a; b++)
            { int c = int.Parse(Console.ReadLine());
                if (PrimeNumbers(c)) s++;
            }
            Console.WriteLine(s);
        }
    }
}