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

int main(void){

  int n,x,i,count=0;

  scanf("%d",&n);
  for(i=0; i < n; i++){
    scanf("%d",&x);
    if(isPrime(x)== 1)count++;
  }
  printf("%d\n",count);
  return 0;
}