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

Ex Input:
Sentence: 'a cat with a pink bow sits underneath something silver'. Replace the letter 'h' with 'n' in the sentence.

Ex Output:
a cat witn a pink bow sits underneatn sometning silver

Ex Input:
Sentence: 'a person with a cell phone standing next to a train'. Replace the letter 's' with 't' in the sentence.

Ex Output:
a perton with a cell phone ttanding next to a train

Ex Input:
Sentence: 'its a sunny day and the train is moving over the bridge'. Replace the letter 'd' with 'l' in the sentence.

Ex Output:
its a sunny lay anl the train is moving over the brilge