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 main(void)
{
  int n,num[10000],i,j,ans=0,jud=0;

  scanf("%d", &n);
  for(i=0;i<n;i++){
    scanf("%d", &num[i]);
    if(num[i]==2||num[i]==3||num[i]==5){
      ans++; continue;
    }
    if(num[i]%2==0) continue;
    for(j=3;j<sqrt(num[i])+1;j+=2){
      if(num[i]%j==0){
	jud=0; break;
      } else {
	jud=1;
      }
    }
    if(jud==1) ans++;
  }
  printf("%d\n", ans);

  return 0;
}