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);
int main(void)
{
	int n, x[10000], i, a = 0;
	
	scanf("%d", &n);
	for (i = 0; i < n; i++) {
		scanf("%d", &x[i]);
	}
	for (i = 0; i < n; i++) {
		if(isprime(x[i]) == 1)
			a++;
	}
	printf("%d\n", a);
	return 0;
}

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