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;

public class my
{
	public static void Main()
	{
		long n = my.GetLong();
		
		long cnt = 0;
		for(int i = 0; i < n; i++ ) {
			if(my.IsPrime(my.GetLong())) { 
				cnt++;
			}
		}
		
		Console.WriteLine(cnt);
	}
	
	public static bool IsPrime(long n)
	{
		if(n == 2) return true;
		
		for(int i = 2; i <= Math.Sqrt(n); i++) {
			if(n%i == 0) return false;
		}
		
		return true;
	}
	
	private static long GetLong()
	{
		return long.Parse(Console.ReadLine());
	}
}