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>
#define N 10000

int main()
{
  int n, a[N], i, j, judge, count=0;

  scanf("%d",&n);

  for(i=0; i<n; i++){
    scanf("%d",&a[i]);
  }

  for(i=0; i<n; i++){
    judge = 0;
    if(a[i] == 2) judge = 0;

    else if(a[i] < 2 || a[i]%2 == 0) judge = 1;
    
    j = 3;
    while(j <= sqrt(a[i])){
      if(a[i]%j == 0){
	judge = 1;
	break;
      }
      j = j+2;
    }

    if(judge == 0) count++;
  }
  
  
  printf("%d\n",count);
  
  return 0;
}