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

Example Input: Sentence: 'a bride and a groom look ridiculous as they stuff cake into each other's mouth'. Replace the letter 'd' with 's' in the sentence.
Example Output: a brise ans a groom look risiculous as they stuff cake into each other's mouth

Example Input: Sentence: 'a man walking a horse on a dirt track'. Replace the letter 't' with 's' in the sentence.
Example Output: a man walking a horse on a dirs srack

Example Input: Sentence: 'a young woman wearing red making an obscene gesture'. Replace the letter 'k' with 'a' in the sentence.
Example Output:
a young woman wearing red maaing an obscene gesture