Reflection Point |2|
~~~~~~~~~~~~~~~~~~~~

Given two points :math:`P(p_x, p_y)` and :math:`Q(q_x, q_y)` in the
two-dimensional plane, we name the point that is in the middle of the
two points the *mid point*, :math:`M(m_x,m_y)`, and the point that is
the 180° rotation of :math:`P` around :math:`Q` the *reflection point*,
:math:`R(r_x,r_y)`.

Consider the following case:

|image1|

Given :math:`P(1,1)` and :math:`Q(3,3)`, we say the mid point :math:`M`
is :math:`M(2,2)` and the reflection point :math:`R` is :math:`R(5,5)`.
It can be seen from the figure that, :math:`Q` is the mid-point of
:math:`P` and :math:`R`, so the distance from :math:`P` to :math:`Q` and
the distance from :math:`Q` to :math:`R` are the same.

Write a program that takes 4 integers as input from the user, the
coordinates of :math:`P` and :math:`Q` *(in the order
:math:`p_x, p_y, q_x, q_y`)*, and prints their mid point and the
reflection point in the order :math:`m_x, m_y, r_x, r_y` as floats with
2 digits after the decimal point.

.. container:: sampleio

   Sample I/O:

.. |2| image:: ../../figures/difficulty_two.png
   :class: difficulty
.. |image1| image:: ../../figures/ch4_reflection_point.png
   :class: width400

.. code:: default

   Input:
   1
   1
   3
   3

   Output:
   2.00
   2.00
   5.00
   5.00

   Input:
   -1
   -1
   1
   1

   Output:
   0.00
   0.00
   3.00
   3.00

   Input:
   4
   5
   1
   2

   Output:
   2.50
   3.50
   -2.00
   -1.00

.. raw:: html

   <button type="button" class="collapsible" onclick="toggle()">

Show the Answer

.. raw:: html

   </button>

.. raw:: html

   <div class="hiddenanswer">

.. code:: python

   px = int(input())
   py = int(input())
   qx = int(input())
   qy = int(input())

   mx = (px + qx) / 2
   my = (py + qy)/2

   rx = qx + (qx - px)
   ry = qy + (qy - py)

   print("{:.2f}".format(mx))
   print("{:.2f}".format(my))
   print("{:.2f}".format(rx))
   print("{:.2f}".format(ry))

.. raw:: html

   </div>