# Learn Recursion by Solving the Tower of Hanoi Puzzle - Step 31

Here is what I had at this step. It does work in a code editor, but doesn’t pass the tests for the challenges. I’m not sure why because the error messaging is a little opaque. I decided to drop the Python course at this step because I was spending a lot of time trying to figure out what the challenge wanted on a lot of these questions.

``````NUMBER_OF_DISKS = 3
number_of_moves = 2**NUMBER_OF_DISKS - 1
rods = {
'A': list(range(NUMBER_OF_DISKS, 0, -1)),
'B': [],
'C': []
}

def make_allowed_move(rod1, rod2):
forward = False
if not rods[rod2]:
forward = True
elif rods[rod1] and rods[rod1][-1] < rods[rod2][-1]:
forward = True
if forward:
print(f'Moving disk {rods[rod1][-1]} from {rod1} to {rod2}')
rods[rod2].append(rods[rod1].pop())
else:
print(f'Moving disk {rods[rod2][-1]} from {rod2} to {rod1}')
rods[rod1].append(rods[rod2].pop())

def move(n, source, auxiliary, target):
# display starting configuration
print(rods)
for i in range(number_of_moves):
remainder = (i + 1) % 3
if remainder == 1:
print(f'Move {i + 1} allowed between {source} and {target}')
make_allowed_move(source,target)
elif remainder == 2:
print(f'Move {i + 1} allowed between {source} and {auxiliary}')
elif remainder == 0:
print(f'Move {i + 1} allowed between {auxiliary} and {target}')
# display our progress
print(rods)

elif remainder == 2:
print(f'Move {i + 1} allowed between {source} and {auxiliary}')
elif remainder == 0:
print(f'Move {i + 1} allowed between {auxiliary} and {target}')
# initiate call from source A to target C with auxiliary B
move(NUMBER_OF_DISKS, 'A', 'B', 'C')
``````

For this step you need to move lines 18 to 31 to the new function.

Here is a comparison of your code and the original code.

The original code is in blue.