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 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;
}

int main(void) {
  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;
}