In this task, you need to replace a letter in the sentence with another given letter.
One example: Sentence: 'group of motorcycle motorists trying to merge into traffic'. Replace the letter 'o' with 'n' in the sentence.
Solution is here: grnup nf mntnrcycle mntnrists trying tn merge intn traffic
Explanation: The letter 'o' has been replaced in the letter 'n'.

Now, solve this: Sentence: 'a den with a couches, a table and several presents'. Replace the letter 'i' with 'e' in the sentence.
Solution:
a den weth a couches, a table and several presents