You will be given a definition of a task first, then some input of the task.
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.

Sentence: 'Prior to joining the Executive Office of the President , Mr. Gips served a three-year tenure as the FCC 's Deputy Chief of the Office of Plans and Policy and later as Chief of the FCC 's International Bureau .', Argument/Subject 1: 'executive', Argument/Subject 2: 'president'
Output:
serve as