Instructions: Given a sentence and two mentions from the text (arguments), indicate a phrase (a verb or noun phrase) that describes the relationship between the provided arguments.
Input: Sentence: 'Punakha once served as the capital of Bhutan and still is the winter seat of Je Khenpo .', Argument/Subject 1: 'punakha', Argument/Subject 2: 'bhutan'
Output:
be capital of