vv...........
                                      ..............v.
                                       ............v.
                                       ...v.......vv
                                       ...vvv.....             ::::::
                                       ...v.vvv             ::::::::::::
                                       .....vv             ::::::::
                                      .......             :::::::
                                     ........             :::::
                                    .........             ::::
                                   .........              :::    vvv::::::
                                  .........              ::::    vv:::::::
                                 ..........              ::::    v:::::::::
                                 .........               :::           ::::
                                .........                :::            ::
                              ......vvv.                 :::
                             .......vv.                  ::::
                            ........v.                   :::::
                           ........v.                    :::
                       vvvv.......vv
                           ......vv