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: Wrong Answer)

is_prime = ->(n) {
  if n == 1 then
    return false
  elsif n == 2 then
    return true
  else
    lim = Math.sqrt(n).to_i + 1
    (2..lim).each do |i|
      if n % i == 0
        return true
      end
    end
    return false
  end
}

res = 0
while line = gets
  n = line.chomp.to_i
  if is_prime.call(n) then
    res += 1
  end
end
puts res