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

Example Input: Sentence: 'a baseball player holding a bat in front of catcher and umpire'. Replace the letter 'i' with 'k' in the sentence.
Example Output: a baseball player holdkng a bat kn front of catcher and umpkre

Example Input: Sentence: 'a black and white picture of a hitter awaiting a pitch while a teammate stands in the on deck circle'. Replace the letter 'a' with 'm' in the sentence.
Example Output: m blmck mnd white picture of m hitter mwmiting m pitch while m temmmmte stmnds in the on deck circle

Example Input: Sentence: 'there is a woman looking in the sky flying a kite'. Replace the letter 'a' with 't' in the sentence.
Example Output:
there is t womtn looking in the sky flying t kite