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 isprime(n)
  2.upto(10000) {|i|
    if(0==(n % i) && (n > i)) 
        return 0
    end
  }
  1
end

n = STDIN.gets.split[0].to_i

cnt=0
0.upto(n-1) {|i| 
  n = STDIN.gets.split[0].to_i
  cnt+=1 if isprime(n)==1
}
p cnt