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

Ex Input:
Sentence: 'a small train is on the tracks by a house'. Replace the letter 'l' with 'x' in the sentence.

Ex Output:
a smaxx train is on the tracks by a house


Ex Input:
Sentence: 'a couple of brown bears walking across a lush green field'. Replace the letter 'w' with 'o' in the sentence.

Ex Output:
a couple of broon bears oalking across a lush green field


Ex Input:
Sentence: 'very nice towel and traffic lights besides the road'. Replace the letter 't' with 'c' in the sentence.

Ex Output:

very nice cowel and craffic lighcs besides che road