public class Logarithmus {
    public static void main(String[] args) {

        double ln2 = 0.0d;
        double counter = 1d;
        boolean check = false;

        for (double i = 1; i <= 1000000; i++) {

            if (i % 2 == 1) {

                ln2 -= 1d - (1 / i);

            } else {

                ln2 += 1d - (1 / i);

            }

            if ((ln2 - Math.log(2) <= 0.0023 && ln2 - Math.log(2) >= 0) ||
            (Math.log(2) - ln2 <= 0.0023 && Math.log(2) - ln2 >= 0)){

                check = true;
                counter++;
            }



        }

        System.out.println(counter);

        /*
        for (double j = ln2; j < Math.log(2); j++) {

            summanden++;
            System.out.println("Abweichung des Ergebnis vom echten Wert um " + summanden + " Stellen.");

        }

        /*if (Math.log(2) == ln2) {

            summanden++;
            System.out.println("Abweichung des Ergebnis vom echten Wert um " + summanden + " Stellen.");

        } */

        System.out.println("Mit der Formel ln2 = " + ln2);
        System.out.println("Probe: Math.log(2) = " + Math.log(2));

    }

}