iirc Last time I looked at this: public static void main(String[] args) throws FileNotFoundException { Scanner s = new Scanner(new File("rounds.txt

iirc Last time I looked at this: public static void main(String[] args) throws FileNotFoundException { Scanner s = new Scanner(new File("rounds.txt")); long rounds = s.nextLong(); s.close(); double sum = 0.0; double flip = -1.0; for (long i = 1; i <= rounds; i++) { flip *= -1.0; sum += flip / (2 * i - 1); } System.out.println(sum * 4.0); } :the measurements changed dramatically if the order was switched something like: sum += flip / (2 * i - 1); flip *= -1.0; YMMV