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

Ex Input:
Sentence: 'a memorial with various plaques and american flags on it'. Replace the letter 'a' with 'k' in the sentence.

Ex Output:
k memorikl with vkrious plkques knd kmerickn flkgs on it


Ex Input:
Sentence: 'a person standing on some skis going through the snow'. Replace the letter 'o' with 'l' in the sentence.

Ex Output:
a persln standing ln slme skis gling thrlugh the snlw


Ex Input:
Sentence: 'a cream colored living room with a cathedral ceiling'. Replace the letter 'w' with 'f' in the sentence.

Ex Output:

a cream colored living room fith a cathedral ceiling