public class euler {
    public static double doorAmt = Math.pow(10,12);
    public static long doorLocation = 0;
    public static long doorsOpened = 0;
    public static boolean stepsDone = false;

    public static void main(String[] args) {
        for (long i = 0; i < doorAmt; i++) {
            if (!stepsDone) {
                doorLocation += (Math.pow(i, 2) + Math.pow(i+1, 2));
                stepsDone = true;
            } if (stepsDone) {
                doorsOpened++;
                stepsDone = false;
            }
        }
    }
}