In this task, you will be given a sentence, and you need to identify the set of coreference words. Coreferences are generally a set of words in the text that refer to the same person or thing. Your output set of coreference words must be strictly present in the given input sentence. Do not use any outside knowledge to create the set of coreference words. If there is a 'the' article before the person or thing you should include 'the' as well. Please separate the coreference words by commas in the output.

Example Input: The carpenter made a desk for the clerk because she needed a desk .
Example Output: the, clerk, she

Example Input: The physician wrote a letter to the writer because he was a fan of one of the writer "'s" books .
Example Output: The, physician, he

Example Input: The guard complimented the designer for meeting his expectations .
Example Output:
The, guard, his