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;

namespace _1_C
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int a = 0;
            for (int i = 0; i < n; i++)
            {
                int x = int.Parse(Console.ReadLine());
                bool z = true;
                if (x == 2)
                {
                    z = true;
                }
                else if (x < 2 || x % 2 == 0)
                {
                    z = false;
                }
                else
                {
                    int j = 3;
                    while (j <= Math.Sqrt(x))
                    {
                        if (x % j == 0)
                        {
                            z = false;
                        }
                        j = j + 2;
                    }
                }
                if (z == true)
                {
                    a++;
                }
            }
            Console.WriteLine(a);
            Console.ReadLine();
        }
    }
}