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 Ruby (judge verdict: Accepted)

#!/usr/bin/ruby
# -*- coding: utf-8 -*-
require "prime"
class Main
  def initialize
    fh = STDIN
    n = fh.gets.chomp.to_i
    count=0
    (1..n).each {|i|
      p = fh.gets.chomp.to_i
      if Prime.prime?(p) then
        count += 1
      end
    }
    puts count
  end
end

if $0==__FILE__ then
  Main.new()
end