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 main(){
    
  int n,a[100000],i,j,f,count=0;
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&a[i]);
    if(a[i]<2 && 1000000<a[i]) break;
  }
    
  for(i=0;i<n;i++){
    f=0;
    if(a[i]==2) f=0;

    else if(a[i]%2==0)f=1;

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