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

Example Input: Sentence: 'a crowd watches as giraffes graze the tree tops at the zoo'. Replace the letter 't' with 'q' in the sentence.
Example Output: a crowd waqches as giraffes graze qhe qree qops aq qhe zoo

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: 'a traffic light is displaying a green smiley face'. Replace the letter 'e' with 'v' in the sentence.
Example Output:
a traffic light is displaying a grvvn smilvy facv