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 );

main(){

  int p,n,i,a,b=0;


  scanf("%d",&n);

  for(i=0;i<n;i++){
    scanf("%d",&p);
    a=isprime(p);
    if(a==1) b++;
  }
  printf("%d\n",b);
  return 0;
}

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