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);

main() {
  
  int i;
  int c=0; //素数カウンタ
  int N; //入力される数
  int A[10000]; //入力された配列

  scanf(" %d", &N);

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

  for( i=0; i<N; i++) {
    c += isPrime( A[i]);
  }

  printf("%d\n", c);

  return 0;

}


int isPrime(int x) {

  //素数なら1,そうでないなら0を返す
  
  int i=3;

  if( x==2) {
    return 1;
  }

  if( x<2 || x%2==0) {
    return 0;
  }

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

  return 1;
}