text: T = [[11, 12, 5, 2], [15, 6, 10], [10, 8, 12, 5], [12, 15, 8, 6]]
  
  T.insert(2, [0, 5, 11, 13, 6])
  del T[2]
  T[2] = [11, 9]
  T[0][3] = 7
  
  for r in T:
      for c in r:
          print(c, end=" ")
      print()
  