Those are already reversed, print the input. Your code revesed only letter in letters resulting in rettels.

Those two sentences are not equal:

'that the the rettel be dedulcni rettels is sdrow is rettels tsisnoc desrever more noitcnuf will sdrow or sdrow that of more a gnirts or five only more'
                                 |     |             |     |
'that the the rettel be dedulcni srettel is sdrow is srettel tsisnoc desrever more noitcnuf will sdrow or sdrow that of more a gnirts or five only more'

The first one is what your function returned btw, not the input.