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

Ex Input:
Sentence: 'a tennis racket is sitting in the middle of a tennis field'. Replace the letter 'i' with 'f' in the sentence.

Ex Output:
a tennfs racket fs sfttfng fn the mfddle of a tennfs ffeld


Ex Input:
Sentence: 'horses drink and graze the field and water'. Replace the letter 'i' with 'c' in the sentence.

Ex Output:
horses drcnk and graze the fceld and water


Ex Input:
Sentence: 'a group of hot dogs grilling on a bbq next to buns'. Replace the letter 'b' with 'f' in the sentence.

Ex Output:

a group of hot dogs grilling on a ffq next to funs