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 <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <math.h>

#define DT_MAX (10000)

int data[DT_MAX];
int out_data[DT_MAX];
int out_data_num;

int main()
{
	int n,i,k,flg;
	char buff[8192];
	double cnt;

	out_data_num = 0;
	gets(buff);
	sscanf(buff,"%d",&n);

	for (i=0 ; i<n ; i++) {
		gets(buff);
		sscanf(buff,"%d",&(data[i]));

	}

	for (i=0 ; i<n ; i++) {
		if (data[i] == 2) {
			out_data[out_data_num] = data[i];
			out_data_num++;
			continue;
		}
		if ((data[i] < 2)||((data[i] % 2)==0)) {
			continue;
		}

		cnt = (int)sqrt((double)data[i]);
		for (flg=1,k=3 ; k<cnt+1 ; k+=2) {
			if ((data[i] % (k))==0) {
				flg=0;
				break;
			}
		}
		if (flg==1) {
			out_data[out_data_num] = data[i];
			out_data_num++;
		}
	}


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