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 isprime(int);


  int main()
{
  int num[N];
  //int prime[N];
  int prime = 0;
  int i,j;


  scanf("%d",&i);
  //printf("i = %d",i);

  for(j = 0 ; j < i ; j++)
    {
      scanf("%d",&num[j]);
    }


  for(j = 0 ; j < i ; j++)
    {
      prime  += isprime(num[j]);
    }
  printf("%d\n",prime);
  return 0;
}

int isprime(int x)
{
  int i;
  double jud;
  
  if(x == 2)return 1;
  if(x < 2 || x % 2 == 0 )return 0;

  i = 3;
  while(i <= sqrt(x)){
    if(x % i == 0)return 0;

    i =  i + 2;
  }

  return 1;
}