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

Ex Input:
Sentence: 'a photo of a river with a train bridge across it'. Replace the letter 'r' with 'f' in the sentence.

Ex Output:
a photo of a fivef with a tfain bfidge acfoss it


Ex Input:
Sentence: 'a table that has a pizza sitting on it'. Replace the letter 'a' with 'w' in the sentence.

Ex Output:
w twble thwt hws w pizzw sitting on it


Ex Input:
Sentence: 'a person holds a robot in front of a ball near a goal'. Replace the letter 'o' with 'b' in the sentence.

Ex Output:

a persbn hblds a rbbbt in frbnt bf a ball near a gbal