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 < 2  || n % 2 == 0
  i = 3 
  while i <= Math.sqrt(n)
    return false if n % i == 0
    i += 2
  end
  true
end

n = gets.to_i
c = 0

n.times do
  x = gets.to_i
  if is_prime(x)
    c += 1
  end
end

p c