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

Example Input: Sentence: 'people walk through a local fruit market in a city'. Replace the letter 'e' with 'n' in the sentence.
Example Output: pnopln walk through a local fruit marknt in a city

Example Input: Sentence: 'a woman is snowboarding down a snowy hill'. Replace the letter 'l' with 'b' in the sentence.
Example Output: a woman is snowboarding down a snowy hibb

Example Input: Sentence: 'two giraffes standing next to each other with other animals in the grass and in the dirt behind them'. Replace the letter 'd' with 'q' in the sentence.
Example Output:
two giraffes stanqing next to each other with other animals in the grass anq in the qirt behinq them