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<algorithm>
# include<cmath>
using namespace std;

bool isprime(int x){
    if(x == 2){
        return true;
    }
    if(x < 2 || x % 2 == 0 ){
        return false;
    }

    int i = 3;
    while(i <= sqrt(x)){
        if(x % i == 0){
            return false;
        };
        i = i + 2 ;
    }
    return true;
}

int main(){
    int n,x,ans;
    cin >> n;
    ans = 0;
    for(int i=0;i<n;i++){
        cin >> x;
        if(isprime(x)){
            ans++;
        }
    }
    cout << ans << endl;
    return 0;
}