Vector<int> list;
    list += 2;
    list += 3;
    for (int i = 1; (i*6 + 1) < 1000; i++) { //create a list of numbers from which to remove non primes from
        list += i*6 - 1;
        list += i*6 + 1;
    }
    for (int j = 0; j < list.size(); j++) {
        //primes += list[j];
        for (int k = (j + 1); k < list.size(); k++) {
            if (list[k] % list[j] == 0) {
                //cout << "removed " << list[k] << " and divided by " << list[j] << endl;
                list.remove(k);
                //k--;
                //j--;
            }
        }
    }