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 <iostream>
#include <cmath>
using namespace std;
int isPrime(int x){
	if(x==2)return true;
	else if(x<2 || x%2==0)return false;
	double xx=x;
	int i=3;
	while(i<=ceil(sqrt(xx))){
		if(x%i==0){
			return false;
		}
		i=i+2;
	}
	return true;
}

int main(){
	int ans=0;
	int n,number;
	cin>>n;
	for(int ii=0;ii<n;ii++){
		cin>>number;
	    ans+=isPrime(number);
	}
	cout<<ans<<endl;
	return 0;
}