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: Time Limit Exceeded)

def gen(m)
    ar=Array.new
    for x in 2..m do
       flg=0
       ar.each do |e|
         if x%e==0 then
            flg=1
            break
         end
       end
       if flg==0 then ar.push(x) end
    end
    return ar
end

n=gets.to_i
ar=Array.new(n)
for i in 0..n-1 do
    ar[i]=gets.to_i
end
er=gen(ar.max)
cnt=0
ar.each do |x|
   if er.include?(x) then cnt+=1 end
end
p cnt