code: def matrix(
          m, n, lst,
          m_text: list=None,
          n_text: list=None):
      
  
      fmt = ""
      if n_text:
          fmt += "     {}\n".format(" ".join(n_text))
      for i in range(1, m+1):
          if m_text:
              fmt += "{:<4.4} ".format(m_text[i-1])
          fmt += "|"
          for j in range(1, n+1):
              if (i, j) in lst:
                  fmt += "x|"
              else:
                  fmt += " |"
          fmt += "\n"
      return fmt
docs: m: row
      n: column
      lst: items
  
      >>> print(_matrix(2, 3, [(1, 1), (2, 3)]))
      |x| | |
      | | |x|