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

Ex Input:
Sentence: 'a close up of a grassy beach showing an umbrella and wind board'. Replace the letter 'a' with 'f' in the sentence.

Ex Output:
f close up of f grfssy befch showing fn umbrellf fnd wind bofrd


Ex Input:
Sentence: 'broccoli and a sweet potato are served on a white plate'. Replace the letter 'o' with 'c' in the sentence.

Ex Output:
brccccli and a sweet pctatc are served cn a white plate


Ex Input:
Sentence: 'a herd of sheep grazing together in a grassy field'. Replace the letter 'y' with 'f' in the sentence.

Ex Output:

a herd of sheep grazing together in a grassf field