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

Ex Input:
Sentence: 'a crooked street sign on a damaged sidewalk'. Replace the letter 'm' with 'u' in the sentence.

Ex Output:
a crooked street sign on a dauaged sidewalk


Ex Input:
Sentence: 'a baseball player is throwing a ball across the dirt field'. Replace the letter 'a' with 't' in the sentence.

Ex Output:
t btsebtll pltyer is throwing t btll tcross the dirt field


Ex Input:
Sentence: 'many birds are flying around large boats docked at a harbor'. Replace the letter 'm' with 'e' in the sentence.

Ex Output:

eany birds are flying around large boats docked at a harbor