class Euler28 {

    private static class Options {
        int size = 1001;
        boolean runCheckpoints = true;
    }

    private static boolean parseIntAfterPrefix(String arg, String prefix, Options options) {
        if (!arg.startsWith(prefix)) {
            return false;
        }
        String tail = arg.substring(prefix.length());
        if (tail.isEmpty()) {
            return false;
        }

        int parsed = 0;
        for (int i = 0; i < tail.length(); i++) {
            char c = tail.charAt(i);
            if (c < '0' || c > '9') {
                return false;
            }
            parsed = parsed * 10 + (c - '0');
        }

        options.size = parsed;
        return true;
    }

    private static boolean parseArguments(String[] args, Options options) {
        for (String arg : args) {
            if ("--skip-checkpoints".equals(arg)) {
                options.runCheckpoints = false;
                continue;
            }
            if (parseIntAfterPrefix(arg, "--size=", options)) {
                continue;
            }

            System.err.println("Unknown argument: " + arg);
            return false;
        }
        return options.size > 0 && (options.size % 2 == 1);
    }

    private static long solve(int size) {
        long total = 1;
        for (int side = 3; side <= size; side += 2) {
            total += 4L * side * side - 6L * (side - 1);
        }
        return total;
    }

    private static boolean runCheckpoints() {
        if (solve(5) != 101L) {
            System.err.println("Checkpoint failed for size=5");
            return false;
        }
        if (solve(7) != 261L) {
            System.err.println("Checkpoint failed for size=7");
            return false;
        }
        return true;
    }

    public static void main(String[] args) {
        Options options = new Options();
        if (!parseArguments(args, options)) {
            System.exit(1);
        }

        if (options.runCheckpoints && !runCheckpoints()) {
            System.exit(2);
        }

        System.out.println(solve(options.size));
    }
}