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 ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int cnt = 0;

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

                bool isPrime = true;

                if (input < 2) isPrime = false;
                else if (input == 2) isPrime = true;
                else if (input % 2 == 0) isPrime = false;
                else
                {
                    for (int j = 3; j <= Math.Sqrt(input); j++)
                    {
                        if (input % j == 0) isPrime = false;
                    }
                }

                if (isPrime) cnt++;
            }

            Console.WriteLine(cnt);
        }
    }
}