In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

Input: Consider Input: A maximum independent set for this data structure can be found in linear time by adding alternating levels. In this structure, any two vertices or nodes must be connected by a single simple path, and thus it is connected and acyclic. By using (*) union-find with disjoint sets, one type of this structure containing all the vertices of a connected graph can be constructed. One variety of this data structure can be used to easily implement a binary search. This structure also comes in red-black and self-balancing-binary varieties. For 10 points, identify this data structure from computer science, a hierarchical graph in which "leaf" nodes ultimately flow from a "root" node.

Output: Science


Input: Consider Input: Vietnamese national hero Le Loi defended his country against this dynasty's forces. The Fish Scale Records were used to calculate taxes by this dynasty's founder, the Hongwu Emperor. This dynasty's Yong-le Emperor ordered the construction of Beijing's Forbidden City. The (*) Yuan Dynasty fell during the Red Turban Rebellion, which brought this dynasty to power. Zheng He was a eunuch admiral who explored under this dynasty's banner. For 10 points, name this Chinese dynasty that began in the 1300s and was renowned for its porcelain.

Output: History


Input: Consider Input: The Cotton-Mouton effect results when it is applied to liquids, while in solids its application results in the Voigt effect, sometimes known as its namesake birefringence. Applying it to metals induces the formation of Landau levels to allow for the measurement of Fermi surfaces, and the propagation of light along the direction of one results in an angular shift proportional to the Verdet constant and is known Faraday rotation. The Lorentz equation gives the force exerted by it on a moving charge, and it is divergence free and can be given as the curl of the vector potential. FTP, identify this field which can be calculated from Ampere's law, the counterpart of the electric field.


Output: Science