In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.

Ex Input:
who is the longest serving director of isro

Ex Output:
Dhawan, Satish


Ex Input:
who is rachel's baby daddy in friends

Ex Output:
Ross


Ex Input:
what type of stone did the romans use

Ex Output:

Travertine limestone