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(double );

int main(){
  int i,n,input,output=0;

  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&input);
  
    if(isPrime((double)input)) 
      output++;
  }
  printf("%d",output);
  printf("\n");

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