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

Ex Input:
Sentence: 'the people are in the library working and studying'. Replace the letter 'r' with 'g' in the sentence.

Ex Output:
the people age in the libgagy wogking and studying


Ex Input:
Sentence: 'an old rusty car sits outside of an old building'. Replace the letter 'o' with 'r' in the sentence.

Ex Output:
an rld rusty car sits rutside rf an rld building


Ex Input:
Sentence: 'an open-faced broiled cheese sandwich served on a plate with cottage cheese in a bowl and a can of v8'. Replace the letter 'd' with 'o' in the sentence.

Ex Output:

an open-faceo broileo cheese sanowich serveo on a plate with cottage cheese in a bowl ano a can of v8