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

Example Input: Sentence: 'a woman sitting on a bench under a gazebo'. Replace the letter 's' with 'u' in the sentence.
Example Output: a woman uitting on a bench under a gazebo

Example Input: Sentence: 'kites flying over a woman wearing a hat'. Replace the letter 'i' with 'j' in the sentence.
Example Output: kjtes flyjng over a woman wearjng a hat

Example Input: Sentence: 'sheep waking along a road near stone houses'. Replace the letter 's' with 'f' in the sentence.
Example Output:
fheep waking along a road near ftone houfef