Given the task definition and input, reply with output. Sometimes users of dialogue systems ask vague questions/queries from the system. In this case, the system asks them a clarifying question to be able to answer it correctly. In this task, you are given a question/query in natural language and your task is to ask a good clarifying question to understand the given question/query more precisely.

Which gps receiver I should buy

are you interested in how gps was orginally made