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>

int isPrime(int x){
  int i;
  if (x<2) return 0;
  else if (x==2) return 1;
  if (x%2==0) return 0;
  for ( i = 3; i*i <= x; i+=2 ){
    if ( x%i==0 ) return 0;
  }
  return 1;
}

int main(){
  int n, i, x;
  int cnt=0;
  scanf("%d", &n);

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

  return 0;
}