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.Collections;
//using System.Linq;

namespace solution
{
  class Class1
  {
    static void Main()
    {
      int n = int.Parse(Console.ReadLine());
      int count = 0;

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

        if (PrimeCheck(x) == true) count++;

      }
      Console.WriteLine(count);
    }

    static bool PrimeCheck(int x)
    {
      if (x == 2) return true;
      if (x % 2 == 0) return false;
      for (int i = 3; i <= Math.Sqrt(x); i += 2)
      {
        if (x % i == 0) return false;
      }
      return true;
    }
  }
}