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>
#include <math.h>

int isPrime(int n);

int main(void)  {
	int i, n, x, num = 0;
	scanf("%d", &n);
	for (i = 0; i < n; i++)  {
	scanf("%d", &x);
		isPrime(x);
  		if (isPrime(x) == 1)
   			num++;
	}
	printf("%d\n", num);
	return 0;
}

int isPrime(int x)  {
	int i;
	if (x == 2)
	 return 1;
 
	if (x < 2 || x % 2 == 0)  
	 return 0;
 
	i = 3;
	while (i <= (double)sqrt(x))  {
		if (x % i == 0)
			return 0;
		i = i + 2;
	}
		return 1;
	
}