/**************************
 * 2.Domácí úloha PPA1
 *
 * @author  Jan Janáček
 * @version 1.00.0000
 */
package ppa1;
/**************************
 * importování lokace a vstupu
 */
import java.util.Locale;
import java.util.Scanner;
/**************************
 * Trida programu
 */
public class Ppa1u02b {
    public static Scanner sc;
    /**************************
     * Hlavni trida Main
     */
    public static void main(String[] args) {
        sc = new Scanner(System.in);
        System.out.print("Zadej Ax: ");
        double Ax = sc.nextInt();
        System.out.print("Zadej Ay: ");
        double Ay = sc.nextInt();
        System.out.print("Zadej Cx: ");
        double Cx = sc.nextInt();
        System.out.print("Zadej Cy: ");
        double Cy = sc.nextInt();
        double Sx = (Ax + Cx)/2;
        double Sy = (Ay + Cy)/2;
        double smer_vektor_X = Cx - Ax;
        double smer_vektor_Y = Cy - Ay;
        double normalX = (smer_vektor_X/2) + (-1);
        double normalY = (smer_vektor_Y/2);

        double Bx = Sx + normalX;
        double By = Sy + normalY;
        double Dx = Sx + normalX * (-1);
        double Dy = Sy + normalY + (-1);
/**************************
 * Výpis
 */
        System.out.format(Locale.US,"Bx %.3f \n",Bx);
        System.out.format(Locale.US,"By %.3f \n",By);
        System.out.format(Locale.US,"Dx %.3f \n",Dx);
        System.out.format(Locale.US,"Dy %.3f \n",Dy);
    }
}