l=0
for o in range(0,len(word)-l):
  
  ...

  l += 1

What you are doing with l has no effect on the for loop, in case you are relying on that somehow. You might as well write for o in range(0, len(word)):...
Also, m just keeps accumulating letters without discrimination. In the end it will simply be a concatenation of the input sequence.

Please use the spoiler tag if you are going to post solution code (even non-working) in the discourse.
Also, if you decide to post code, use markdown formatting:

```

your code

```

Otherwise, we can't make heads or tails from what you wrote (indentation matters in python).