__--~~~~~~~--__
        _-~~     _>A<_     ~~-_
      /~>V<~     \ H /     ~>V<~\
    /~/~ | ~\_|-_ ~V~ _-|_/~ | ~\~\
   /=>--   --<===>-+-<===>--   --<=\
  /-|~\_ | _/~|-~ _A_ ~-|~\_ | _/~|-\
 f     _>A<_     / H \     _>A<_     ?
f~     \ H /     ~>V<~     \ H /     ~?
|~\_|-_ ~V~ _-|_/~ | ~\_|-_ ~V~ _-|_/~|
|--<===>-+-<===>--   --<===>-+-<===>--|
|_/~|-~ _A_ ~-|~\_ | _/~|-~ _A_ ~-|~\_|
t_     / H \     _>A<_     / H \     _j
 t     ~>V<~     \ H /     ~>V<~     j
  \-|_/~ | ~\_|-_ ~V~ _-|_/~ | ~\_|-/   =W.L.=
   \=>--   --<===>-+-<===>--   --<=/
    \_\_ | _/~|-~ _A_ ~-|~\_ | _/_/
      \_>A<_     / H \     _>A<_/
        ~-__     ~>V<~     __-~
            ~~--_______--~~

            [===> [0] <===]