public class Rectangle {
    private int x1, y1, x2, y2;

    public Rectangle(int x1, int y1, int x2, int y2) {
        if (x1 < 0 || y1 < 0 || x2 < 0 || y2 < 0) {
            throw new IllegalArgumentException("Coordinates must be in the first quadrant");
        }
        this.x1 = x1;
        this.y1 = y1;
        this.x2 = x2;
        this.y2 = y2;
    }

    public Rectangle(int width, int height) {
        if (width < 0 || height < 0) {
            throw new IllegalArgumentException("Width and height must be positive");
        }
        this.x1 = 0;
        this.y1 = 0;
        this.x2 = width;
        this.y2 = height;
    }

    public Rectangle() {
        this.x1 = 0;
        this.y1 = 0;
        this.x2 = 0;
        this.y2 = 0;
    }
}