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)

#include<stdio.h>

int isPrime(int x) {
    int i;
    if (x < 2) return 0;
    else if (x == 2) return 1;
    if (x % 2 == 0) return 0;
    for (i = 3; i * i <= x; i++) {
        if (x % i == 0) return 0;
    }
    return 1;
}

int main() {
    int n, x, i;
    int cnt = 0;
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        scanf("%d", &x);
        if (isPrime(x)) cnt++;
    }
    printf("%d\n", cnt);
    
    return 0;
}