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)

def prime(a)
  b = Array.new
  k = 0
  for i in 1..a.length-1
    if a[i] == 2 or a[i] == 3
      b[k] = a[i]
      k += 1
      next
    elsif a[i] % 2 != 0
      j = 3
      while a[i] % j != 0
        j += 2
        if j >= a[i]/2
          b[k] = a[i]
          k += 1
          break
        end
      end
    end
  end
  print(b)
  return k
end