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 Scala (judge verdict: Accepted)

import scala.io.StdIn.readInt

object Main extends App {
  val n = readInt
  var ans = 0

  for (_ <- 1 to n) {
    val num = readInt
    if (isPrime(num)) ans += 1
  }

  println(ans)

  def isPrime(x: Int): Boolean = {
    if (x == 2) true
    else if (x < 2 || x % 2 == 0) false
    else {
      var i = 3
      while (i <= Math.sqrt(x)) {
        if (x % i == 0) return false
        i = i + 2
      }
      true
    }
  }
}