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)

class Integer
  def is_prime?
    return true if self == 2

    return false if self < 2 || (self % 2 == 0)

    sqrt = Math.sqrt(self)
    3.step(sqrt, 2) do |i|
      return false if self % i == 0
    end

    true
  end
end

answer = 0
count = gets.chomp.to_i
count.times do
  n = gets.chomp.to_i
  answer += 1 if n.is_prime?
end

puts answer