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)

def is_prime?(n)
  return true if n == 2
  return false if n <= 1 || n.even?
  3.step(Math.sqrt(n), 2) { |x| return false if n.modulo(x).zero? }
  return true
end

n = gets.to_i
ns = []
n.times { ns << gets.to_i }
puts ns.map{ |x| lambda{|y| (is_prime?(y) ? 1 : 0) }.call(x) }.inject(&:+)