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>
#define N 10000
int prime(double x);
int main(){
  int i,n,a[N],count=0;
  scanf("%d",&n);
  for(i=0;i<n;i++){ 
    if(scanf("%d",&a[i])==EOF) break;
    count+=prime((double)a[i]);
  }
  printf("%d\n",count);
  return 0;
}

int prime(double a){
  int i; 
  if(a==2)
    return 1;
  if(a<2 || ((int)a%2)==0)
    return 0;

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

}