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.Linq;
using System.Text;

namespace Practice
{
    class Program
    {
        private static int ReadAndParseInt()
        {
            return int.Parse(Console.ReadLine());
        }
        private static int[] ReadAndParseIntArr()
        {
            return Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
        }
        private static long ReadAndParseLong()
        {
            return long.Parse(Console.ReadLine());
        }
        private static long[] ReadAndParseLongArr()
        {
            return Array.ConvertAll(Console.ReadLine().Split(' '), long.Parse);
        }
        static void Main(string[] args)
        {
            //SolveA(args);
            SolveB(args);
            //SolveC(args);
            //SolveD(args);


        }
        
        private static void SolveB(string[] args)
        {
            int n = ReadAndParseInt();
            int sum = 0;
            for(int i=0;i<n;++i)
            {
                int val = ReadAndParseInt();
                if( IsPrime(val))
                {
                    sum++;
                }
            }
            Console.WriteLine(sum);
        }
        private static bool IsPrime(int val)
        {
            if( val == 1) { return false; }
            if( val == 2) { return true; }
            if( val % 2 == 0) { return false; }

            double sqrt = Math.Sqrt(val);
            int max = (int)Math.Ceiling(sqrt);
            for(int i=3; i <=max;i+=2)
            {
                if( val % i == 0) { return false; }
            }
            return true;
        }
    }
}