In this task, you need to replace a letter in the sentence with another given letter.

Let me give you an example: Sentence: 'group of motorcycle motorists trying to merge into traffic'. Replace the letter 'o' with 'n' in the sentence.
The answer to this example can be: grnup nf mntnrcycle mntnrists trying tn merge intn traffic
Here is why: The letter 'o' has been replaced in the letter 'n'.

OK. solve this:
Sentence: 'a lit merry go round a dusk on a dock'. Replace the letter 'a' with 'o' in the sentence.
Answer:
o lit merry go round o dusk on o dock