axes

-- /~-__A__-~\ --------------- /~-__A__-~\ --
  |     H     |               |     H     |
  |     H     |               |     H     |
   \_-~~H~~-_/                 \_-~~H~~-_/
        H                           H
        H                           H
        H                           H
        H                           H
------- U ------------------------- U -------