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

Input: Consider Input: Sentence: 'busy city street with pedestrians and cars with lights all around'. Replace the letter 'r' with 'k' in the sentence.

Output: busy city stkeet with pedestkians and caks with lights all akound

Input: Consider Input: Sentence: 'the big sandwich features several different colorful ingredients'. Replace the letter 'e' with 'o' in the sentence.

Output: tho big sandwich foaturos sovoral difforont colorful ingrodionts

Input: Consider Input: Sentence: 'a passenger train at a station made by keio'. Replace the letter 'a' with 'u' in the sentence.
Output: u pussenger truin ut u stution mude by keio