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

Example Input: Sentence: 'a rose that is sitting in a vase'. Replace the letter 'r' with 'j' in the sentence.
Example Output: a jose that is sitting in a vase

Example Input: Sentence: 'a gate with a stop sign blocking the road'. Replace the letter 'h' with 'y' in the sentence.
Example Output: a gate wity a stop sign blocking tye road

Example Input: Sentence: 'a man swinging a bag as people watch him'. Replace the letter 'g' with 'k' in the sentence.
Example Output:
a man swinkink a bak as people watch him