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

Ex Input:
Sentence: 'the dog lies inside a purple and white collapsable chair'. Replace the letter 'n' with 'j' in the sentence.

Ex Output:
the dog lies ijside a purple ajd white collapsable chair

Ex Input:
Sentence: 'a guy looking at a tennis ball with a goofy look'. Replace the letter 'a' with 'x' in the sentence.

Ex Output:
x guy looking xt x tennis bxll with x goofy look

Ex Input:
Sentence: 'a pizza with a pizza cutter next to it'. Replace the letter 'z' with 'j' in the sentence.

Ex Output:
a pijja with a pijja cutter next to it