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 Rust (judge verdict: Accepted)

#![allow(non_snake_case)]

use std::io;
use std::io::prelude::*;

/// 素因子判定により高速化
fn is_prime(num: u32) -> bool {
    if num == 2 {
        return true;
    } else if num < 2 || num % 2 == 0 {
        return false;
    }

    let mut i = 3;
    let end = (num as f64).sqrt() as u32;
    while i <= end {
        if num % i == 0 {
            return false;
        }
        i += 2;
    }
    return true;
}

fn main() {
    let sin = io::stdin();
    let mut l_iter = sin.lock().lines();

    let _n: usize = l_iter.next().unwrap().unwrap().trim().parse().unwrap();

    let mut cnt = 0;
    for line in l_iter {
        let l = line.unwrap();
        let d: u32 = l.trim().parse().unwrap();
        if is_prime(d) {
            cnt += 1;
        }
    }
    println!("{}", cnt);
}