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: Runtime Error)

using System;

class Program
{
    static bool[] isNotPrime = new bool[100000001];
    static bool[] isUsed = new bool[10000001];
    static void Main()
    {
        isNotPrime[1] = true;
        for (int i = 2; i < 10000001; i++)
        {
            if (isNotPrime[i]) continue;
            for (int j = 2; j * i < 10000001; j++) isNotPrime[j * i] = true;
        }
        int counter = 0;
        while (true)
        {
            string raw = Console.ReadLine();
            if (raw == null) break;
            int input = int.Parse(raw);
            if (!isNotPrime[input] && !isUsed[input])
            {
                counter++;
                isUsed[input] = true;
            }
        }
        Console.WriteLine(counter);
        return;
    }
}