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

Ex Input:
Sentence: 'a couple of giraffe standing next to each other'. Replace the letter 'i' with 'q' in the sentence.

Ex Output:
a couple of gqraffe standqng next to each other


Ex Input:
Sentence: 'a boy riding his skate board on an obstacle course'. Replace the letter 'e' with 'b' in the sentence.

Ex Output:
a boy riding his skatb board on an obstaclb coursb


Ex Input:
Sentence: 'a double deckered bus with trees in the background'. Replace the letter 'o' with 'i' in the sentence.

Ex Output:

a diuble deckered bus with trees in the backgriund