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 ALDS1
{
    class Program
    {
        private static int Prime(int a)
        {
            for(int i = 2; i <= Math.Sqrt(a); i++)
                if (a % i == 0) return 0;
            return 1;
        }

        static void Main()
        {
            int c = 0;
            int l = int.Parse(Console.ReadLine());
            while ( l-- > 0)
                c += Prime(int.Parse(Console.ReadLine()));
            Console.WriteLine(c);
        }
    }
}