import java.util.*; public class Main { static class Point { public double x, y; public Point(double x, double y) { this.x = x; this.y = y; } public Point() { this(0.0, 0.0); } } static class Line { public Point point_A, point_B; public Line(Point a, Point b) { point_A = a; point_B = b; } public Lin...