Extract the account numbers from an old text file.

    _  _     _  _  _  _  _
  | _| _||_||_ |_   ||_||_|
  ||_  _|  | _||_|  ||_| _|

Each account number is written on 4 lines: 3 with characters, followed by one blank line.

domcode.org/ocr.txt

Original source: https://code.joejag.com/coding-dojo/bank-ocr/