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_1_C_PrimeNumbers
{
	class Program
	{
		static void Main ( string[] args )
		{
			int dataCount = int.Parse (Console.ReadLine ());

			int count = 0;

			for (int lp = 0; lp < dataCount; lp++)
			{
				int inputNum = int.Parse (Console.ReadLine ());
				if (IsPrimeNumber (inputNum))
					count++;
			}

			Console.WriteLine (count);
		}

		static bool IsPrimeNumber ( int num )
		{
			if (num < 2)
				return false;

			if (num == 2)
				return true;

			if (num % 2 == 0)
				return false;

			int lp = 3;
			double limit = Math.Sqrt (num);
			while (lp <= limit)
			{
				if (num % lp == 0)
					return false;

				lp += 2;
			}

			return true;
		}
	}
}