[
    [
        [[[[["a", "b"], "c"], ["d", "e"]], [[["f", "g"], "h"], [["i", "j"], ["k", ["l", "m"]]]]], 
        ["n", [[["o", "p"], "q"], ["r", "s"]]]], ["t", ["u", "v"]]
    ], 
    [["w", ["x", "y"]], "z"]
]

##</code><code>##

[0
    [1
    .   [2
    .   .   [3
    .   .   .   [4
    .   .   .   .   [5
    .   .   .   .   .   [6
    .   .   .   .   .   .   "a",
    .   .   .   .   .   .   ."b"
    .   .   .   .   .   ],
    .   .   .   .   .   "c"
    .   .   .   .   ],
    .   .   .   .   [5
    .   .   .   .   .   "d",
    .   .   .   .   .   "e"
    .   .   .   .   ]
    .   .   .   ],
    .   .   .   [4
    .   .   .   .   [5
    .   .   .   .   .   [6
    .   .   .   .   .   .   "f",
    .   .   .   .   .   .   "g"
    .   .   .   .   .   ],
    .   .   .   .   .   "h"
    .   .   .   .   ],
    .   .   .   .   [5
    .   .   .   .   .   [6
    .   .   .   .   .   .   "i",
    .   .   .   .   .   .   "j"
    .   .   .   .   .   ],
    .   .   .   .   .   [6
    .   .   .   .   .   .   "k",
    .   .   .   .   .   .   [7
    .   .   .   .   .   .   .   "l",
    .   .   .   .   .   .   .   "m"
    .   .   .   .   .   .   ]
    .   .   .   .   .   ]
    .   .   .   .   ]
    .   .   .   ],
    .   .   ],
    .   .   [3
    .   .   .   "n",
    .   .   .   [4
    .   .   .   .   [5
    .   .   .   .   .   [6
    .   .   .   .   .   .   "o",
    .   .   .   .   .   .   "p"
    .   .   .   .   .   ],
    .   .   .   .   .   "q"
    .   .   .   .   ],
    .   .   .   .   [5
    .   .   .   .   .   "r",
    .   .   .   .   .   "s"
    .   .   .   .   ]
    .   .   .   ]
    .   .   ],
    .   ],
    .   [2
    .   .   "t",
    .   .   [3
    .   .   .   "u",
    .   .   .   "v"
    .   .   ]
    .   ],
    ],
    [1
    .   [2
    .   .   "w",
    .   .   [
    .   .   .   "x",
    .   .   .   "y"
    .   .   ]
    .   ],
    .   "z"
    ],
]

##</code><code>##

                                                ___________/\____________
                               ________________/\____________         __/\_
                 _____________/\______________              /\       /\    \
        ________/\________                ___/\___         /  \     /  \    z
     __/\__         _____/\____          /     __/\__     t   /\   w   /\
    /\     \       /\       __/\__      n     /\     \       u  v     x  y
   /  \    /\     /  \     /     /\          /  \    /\
  /\   c  d  e   /\   h   /\    /  \        /\   q  r  s
 a  b           f  g     i  j  k   /\      o  p
                                  l  m