In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Example Input: What was formed in 1850 to help with policing?, Context: In the American Old West, policing was often of very poor quality.[citation needed] The Army often provided some policing alongside poorly resourced sheriffs and temporarily organized posses.[citation needed] Public organizations were supplemented by private contractors, notably the Pinkerton National Detective Agency, which was hired by individuals, businessmen, local governments and the federal government. At its height, the Pinkerton Agency's numbers exceeded those of the United States Army.[citation needed]
Example Output: Pinkerton National Detective Agency

Example Input: What led to the result that observers in relative motion measure different elapsed times?, Context: In non-relativistic classical mechanics, Newton's concept of "relative, apparent, and common time" can be used in the formulation of a prescription for the synchronization of clocks. Events seen by two different observers in motion relative to each other produce a mathematical concept of time that works sufficiently well for describing the everyday phenomena of most people's experience. In the late nineteenth century, physicists encountered problems with the classical understanding of time, in connection with the behavior of electricity and magnetism. Einstein resolved these problems by invoking a method of synchronizing clocks using the constant, finite speed of light as the maximum signal velocity. This led directly to the result that observers in motion relative to one another measure different elapsed times for the same event.
Example Output: a method of synchronizing clocks

Example Input: Who did others look to to hear about the new system?, Context: Although little was officially announced by Chinese authorities about the signals of the new system, the launch of the first COMPASS satellite permitted independent researchers not only to study general characteristics of the signals, but even to build a COMPASS receiver.
Example Output:
authorities

