public class Main {
public static void main(String[] args) {
System.out.println(Math.atan(0.5));
System.out.println(Math.atan(-0.5));
System.out.println(Math.atan(5));
System.out.println(Math.atan(-5));
System.out.println(Math.atan(100));
System.out.println(Math.atan(-100));
}
}