#include <iostream>
using namespace std;

bool check_prime(int);

int main() {

    int n;

    cout<<"Enter a positive integer: ";
    cin>>n;

    if(check_prime(n))
        cout<<n<<" is a prime number.";
    else
        cout<<n<<"is not a prime number.";

    return 0;
}

bool check_prime(int n){
    bool is_prime=true;

    //0 and 1 are not prime numbers
    if(n==0 || n==1){
        is_prime=false;
    }

    for(int i=2;i<=n/2;++i){
        if(n % i == 0){
            is_prime=false;
            break;
        }
    }

    return is_prime;
}