import java.util.*; public class Main { private Scanner sc; private Main() { this.sc = new Scanner(System.in); } private void doIt() { System.out.printf("Input a number: "); double d = sc.nextDouble(); double res = d; for(int i=0; i<100; i++) { res = (res + d / res) / 2; } System.out.printf("%.15f\n", res); } public static void main(String[] args) { new Main().doIt(); } }