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

Ex Input:
Sentence: 'a yellow fire truck parked in a parking lot'. Replace the letter 'a' with 'y' in the sentence.

Ex Output:
y yellow fire truck pyrked in y pyrking lot

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

Ex Output:
a jose that is sitting in a vase

Ex Input:
Sentence: 'there are two elephants that are embracing in the wild'. Replace the letter 'h' with 'u' in the sentence.

Ex Output:
tuere are two elepuants tuat are embracing in tue wild