prompt: Your task is to convert an English description into an ASCII tree format using this style:
  ```
  main
   +--java
   |   `--org
   |       `--gradle
   |           `--sample
   `--webapp
  ```
  
  Convert this description:
  
  app is a top-level directory that gathers 3 subdirectories: base, catchall and optional-catchall.
  At the main level, 'base' encompasses 1 subfolders: [param1].
  At level 2, in directory path 'base > [param1]', '[param1]' possesses 1 nested folders: [param2].
  In nested path 'base / [param1] / [param2]', Inside '[param2]', you'll find it is an empty container.
  At the main level, 'catchall' bundles 1 subdirectory elements: [...params].
  Within directory hierarchy 'catchall / [...params]', '[...params]' is currently empty.
  At the main level, 'optional-catchall' includes 1 directory entries: [[...params]].
  At level 2, in directory path 'optional-catchall > [[...params]]', '[[...params]]' stands empty.
  Back to the top level.
  
  
  Provide your answer wrapped in <ascii_formatted> tags.
verification_info: {"ground_truth": "app\n +--base\n |   `--[param1]\n |       `--[param2]\n +--catchall\n |   `--[...params]\n `--optional-catchall\n     `--[[...params]]", "description": "app is a top-level directory that gathers 3 subdirectories: base, catchall and optional-catchall.\nAt the main level, 'base' encompasses 1 subfolders: [param1].\nAt level 2, in directory path 'base > [param1]', '[param1]' possesses 1 nested folders: [param2].\nIn nested path 'base / [param1] / [param2]', Inside '[param2]', you'll find it is an empty container.\nAt the main level, 'catchall' bundles 1 subdirectory elements: [...params].\nWithin directory hierarchy 'catchall / [...params]', '[...params]' is currently empty.\nAt the main level, 'optional-catchall' includes 1 directory entries: [[...params]].\nAt level 2, in directory path 'optional-catchall > [[...params]]', '[[...params]]' stands empty.\nBack to the top level.\n"}