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 eratosthenes(n)
	table = Array.new(n + 1,true)
	prime_list = []

	(2..n).each do |num|
			if table[num] == true
				prime_list << num
			k = num * num
			while k <= n
				table[k] = false
				k += num
			end
		end
	end
	return prime_list
end

def main()
	n = gets.to_i
	a = []
	n.times.each { |i|
		a.push(gets.to_i)
	}
	primes = eratosthenes(10000)
	cnt = 0
	a.each { |e|
		if primes.include?(e) then
			cnt += 1
		end
	}
	puts cnt
end

main