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

int main(){
 
  int n,res=0;
  int i;
  int A[10000];
   
  scanf("%d",&n);
 
  for(i=0;i<n;i++){
    scanf("%d",&A[i]);
  }
  for(i=0;i<n;i++){
    if(isprime(A[i])==0) res++;
  }
  printf("%d\n",res);
 
  return 0;
}