Instructions: Indicate all the pronouns (they, them, you, he, his, her, you, it, etc.) present in the given sentence. If there are multiple such pronouns in a sentence, then list them in the order of their first appearance in the given sentence. If a pronoun appears multiple times in a sentence, list it only once.
Input: bob paid for charlie's college education, but now charlie acts as though it never happened. he is very ungrateful.
Output:
it, he