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)

N = gets.to_i
a = Array.new(N){0}
N.times do |i|
a[i] = gets.to_i
end
a.sort
prime = Array.new
jd = true
count=0
prime.unshift(2)
2.upto(10000) do |i|
	jd = true
prime.each do |n|
	if i%n== 0
		jd=false
		break
	end
end
if jd ==true
	prime.unshift(i)
end
end

N.times do |i|
	jd = true
prime.each do |n|
	if(n==a[i])
		count+=1
		prime.unshift(a[i])
		jd = false
		break
	end
end
if jd==false
	next
end

prime.each do |n|
if(a[i] % n==0)
	jd = false
	break
end
end
if jd == true 
	prime.unshift(a[i])
	count+=1
	end
end

puts count