private static int findMeADivisor(int num) {
        for (int prime : some_primes)
            if (num % prime == 0)
                return prime;
        
        //otherwise...
        System.out.println("I've had to bruteforce it...");
        
        for (int i = some_primes[some_primes.length - 1] + 1; i < num; i++)
            if (num % i == 0)
                return i;
        
        throw new RuntimeException("frick it @ " + num);
    }