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 main(){

  int n, a[N], i, j, flag=0, count=0;

  scanf("%d",&n);

  for(i=0;i<n;i++){
    scanf("%d",&a[i]);
    if(a[i]==1)flag=1;
    else if(a[i]==2||a[i]==3)flag=0;
    else if(a[i]%2==0)flag=1;
    else{
    for(j=3;j<=sqrt(a[i]);j++){
      if(a[i]%j==0){
	flag=1;
	break;
      }}}
    if(flag==0)count++;
    flag=0;
  }
  printf("%d\n",count);

  return 0;
}