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

Input: Consider Input: Sentence: 'a giraffe standing alone with a low fence behind it'. Replace the letter 't' with 'o' in the sentence.

Output: a giraffe soanding alone wioh a low fence behind io


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

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


Input: Consider Input: Sentence: 'a photo of a river with a train bridge across it'. Replace the letter 'r' with 'f' in the sentence.


Output: a photo of a fivef with a tfain bfidge acfoss it