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
nums = []
n.times {
    nums.push( gets.to_i )
}

cnt = n
for i in ( 0 ... nums.length )
	if 2 == nums[i]
		next
	end
	if 0 == nums[i]%2
		cnt-=1
		next
	end
	3.step( Math.sqrt(nums[i]), 2 ) { |j|
		if 0 == nums[i]%j
			cnt-=1
			break
		end
	}
end

puts( cnt )