    integer x_1, y_1, x_2, y_2, a, b, x_3, y_3, x_4, y_4
    read *, x_1, y_1, x_2, y_2
    a = x_2 - x_1
    b = y_2 - y_1
    x_3 = x_2 - b
    y_3 = y_2 + a
    x_4 = x_3 - a
    y_4 = y_3 - b
    print *, x_3, y_3, x_4, y_4
END