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;

class Program{
    public static void Main(){
        var n=int.Parse(Console.ReadLine());
        var a=new int[n];
        for(var i=0; i<n; i++){
            a[i]=int.Parse(Console.ReadLine());
        }

        var cnt=0;
        for(var i=0; i<n; i++){
            var ai=a[i];
            if(ai!=2 && ai%2==0){
                continue;
            }
            var flag=true;
            for(var j=3; j*j<=ai; j+=2){
                if(ai%j==0){
                    flag=false;
                    break;
                }
            }
            if(flag){
                cnt++;
            }
        }

        Console.WriteLine(cnt);
    }
}