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.Text;

class Program
{
    public void Proc()
    {
        int itemCount = int.Parse(Console.ReadLine());
        int[] numList = new int[itemCount];
        int sosuCount = 0;
        for(int i=0; i<itemCount; i++)
        {
            int num = int.Parse(Console.ReadLine());
            numList[i] = num;
            if(this.IsSosu(num))
            {
                sosuCount++;
            }
        }
        Console.WriteLine(sosuCount);
    }

    private bool IsSosu(int num)
    {
        if(num == 2)
        {
            return true;
        } else if(num < 2 || num % 2 == 0)
        {
            return false;
        }
        int max = (int)( Math.Sqrt(num)) + 1;
        for (int i = 2; i <= max; i++) {
            if(num % i == 0)
            {
                return false;
            }
        }
        return true;
    }

    static void Main(string[] args)

    {

        Program prg = new Program();
        prg.Proc();

    }
}