 the same thing.
Let us imagine that we have done this, and say how later:

o-------------------------------------------------o
|                                                 |
|        o                               o        |
|        |\                             /|        |
|        | \                           / |        |
|        |  \                         /  |        |
|        |   \                       /   |        |
|        |    \                     /    |        |
|        |     \    