class Point {
int x, y;
Point(int x, int y) { this.x = x; this.y = y; }
}
class ColoredPoint extends Point {
static final int WHITE = 0, BLACK = 1;
int color;
ColoredPoint(int x, int y) {
this(x, y, WHITE);
}
ColoredPoint(int x, int y, int color) {
super(x, y);
this.color = color;
}
}