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 C (judge verdict: Accepted)

// 1_1_C
#include <stdio.h>
#include <math.h>

int is_prime(long);

int main(){
    int n, i, cnt = 0;
    long number;
    scanf("%d", &n);

    for(i = 0; i < n; i++){
        scanf("%ld", &number);
        if(is_prime(number) == 0){
            cnt += 1;
        }
    }

    printf("%d\n", cnt);
    return 0;
}

int is_prime(long number){
    if(number == 2) return 0;
    if(number % 2 == 0) return 1;

    long divisor;
    for(divisor = 3; divisor <= sqrt(number); divisor += 2){
        if(number % divisor == 0) return 1;
    }
    return 0;
}