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(long);

int main(){
  int N, n, t = 0;
  long L;

  scanf("%d\n",&N);

  for(n = 0; n < N; n++){
    scanf("%ld\n", &L);
    if (L==2){
       t++;
    }else if(L>2){
       t+=isprime(L);
    }
  }
  printf("%d\n",t);
  return 0;
}

int isprime(long L){
  long i = 3;
  long Ls = (long)sqrt(L);
  if (!(L%2)){
      return 0;
  }
  while (i <= Ls){
    if(!(L%i)){
       return 0;
    }
    i += 2;
  }
  return 1;
}