// PrimeTestNonModular.java
// Aaron Tan
// This program reads in a positive integer and determines
// if it is a prime number.
// This is a non-modular version.

import java.util.*;

class PrimeTestNonModular {
 
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.print("Enter a positive integer: ");
        int number = sc.nextInt();

        boolean isPrime = true;
        int divisor = 2;

        while (isPrime && (divisor < Math.sqrt(number)+1)) {
            if (number % divisor == 0) 
                isPrime = false;
            divisor++;
        }

        if (number == 1)
            System.out.println(number + " is not a prime.");
        else if (number == 2 || isPrime)
            System.out.println(number + " is a prime.");
        else
            System.out.println(number + " is not a prime.");

    }

}