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

Ex Input:
Sentence: 'a herd of black cattle grazing and lounging in a green field'. Replace the letter 'a' with 'q' in the sentence.

Ex Output:
q herd of blqck cqttle grqzing qnd lounging in q green field


Ex Input:
Sentence: 'a polar bear relaxing in a man-made pool'. Replace the letter 'r' with 'x' in the sentence.

Ex Output:
a polax beax xelaxing in a man-made pool


Ex Input:
Sentence: 'two mannequins one dressed in white the other in black'. Replace the letter 'n' with 'j' in the sentence.

Ex Output:

two majjequijs oje dressed ij white the other ij black