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

Example Input: Sentence: 'a number of people sitting on chairs near each other'. Replace the letter 'c' with 'm' in the sentence.
Example Output: a number of people sitting on mhairs near eamh other

Example Input: Sentence: 'a man rolling dough in the kitchen'. Replace the letter 'a' with 'e' in the sentence.
Example Output: e men rolling dough in the kitchen

Example Input: Sentence: 'a boy hit s a tennis ball with panache'. Replace the letter 'n' with 'r' in the sentence.
Example Output:
a boy hit s a terris ball with parache