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 isprime(int);
int main()
{
  int n,i,j,count=0;
  int x;

  scanf("%d",&n);
  for(i=0; i<n; i++) {
    scanf("%d",&x);
    if(!isprime(x)) count++;
  }
  
  printf("%d\n",count);
    
  return 0;
}

int isprime(int x) 
{
  int i=3;
  if(x==2) return 0;
  else if(x<2 || x%2==0) return	1;
  else {
    while(i<=sqrt(x)){
      if(x%i==0) return 1;
      i += 2;
    }
  }
  return 0;
}