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)

a = []
gets.chomp.to_i.times do
  a.push(gets.chomp.to_i)
end

n = 0
a.each do |item|
  if item == 2
    n += 1
  else
    bool = true
    i = 3
    bool = false if item % 2 == 0
    until i > Math.sqrt(item) || bool == false
      bool = false if item % i == 0
      i += 2
    end
    n += 1 if bool == true
  end
end

puts n