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 i,j,n,count=0;
  int num[N];
  
  scanf("%d",&n);

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

  for(i=0; i<n; i++){
    
    if(isprime(num[i])==1) count++;

    }

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

int isprime(int x){

  int i;
  
  if(x == 2) return 1;

  if(x<2 || x%2==0) return -1;

  i=3;

  while (i<=sqrt(x)){
    
    if (x%i==0) return -1;

    i=i+2;
  }
  
  return 1;
  
}