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

Ex Input:
Sentence: 'a hipster riding a skateboard up the side of a wall'. Replace the letter 's' with 'm' in the sentence.

Ex Output:
a hipmter riding a mkateboard up the mide of a wall

Ex Input:
Sentence: 'a herd of cattle standing on a lush green field'. Replace the letter 'g' with 'f' in the sentence.

Ex Output:
a herd of cattle standinf on a lush freen field

Ex Input:
Sentence: 'a young man jumps into the air while his skateboard twirls'. Replace the letter 'e' with 'w' in the sentence.

Ex Output:
a young man jumps into thw air whilw his skatwboard twirls