human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "raising np lower bounds to parallel np lower bounds"
  Abstract: A decade ago, a beautiful paper by Wagner developed a ``toolkit'' that in certain cases allows one to prove problems hard for parallel access to NP. However, the problems his toolkit applies to most directly are not overly natural. During the past year, problems that previously were known only to be NP-hard or coNP-hard have been shown to be hard even for the class of sets solvable via parallel access to NP. Many of these problems are longstanding and extremely natural, such as the Minimum Equivalent Expression problem (which was the original motivation for creating the polynomial hierarchy), the problem of determining the winner in the election system introduced by Lewis Carroll in 1876, and the problem of determining on which inputs heuristic algorithms perform well. In the present article, we survey this recent progress in raising lower bounds.

Connected through hyperedge HE-1 (induced by source paper "computational social choice and computational complexity bffs"):
  with members:
    - "consensus halving is ppa complete"
    - "online voter control in sequential elections"
    - "the complexity of online manipulation of sequential elections"
    - "hybrid elections broaden complexity theoretic resistance to control"
    - "a richer understanding of the complexity of election systems"
    - "exact analysis of dodgson elections lewis carroll s 1876 voting system is complete for parallel access to np"

Connected through hyperedge HE-2 (induced by source paper "the complexity of computing minimal unidirectional covering sets"):
  with members:
    - "hybrid elections broaden complexity theoretic resistance to control"
    - "a richer understanding of the complexity of election systems"
    - "recognizing when heuristics can approximate minimum vertex covers is complete for parallel access to np"
    - "exact complexity of the winner problem for young elections"
    - "exact analysis of dodgson elections lewis carroll s 1876 voting system is complete for parallel access to np"

Connected through hyperedge HE-3 (induced by source paper "a richer understanding of the complexity of election systems"):
  with members:
    - "hybrid elections broaden complexity theoretic resistance to control"
    - "dichotomy for voting systems"
    - "anyone but him the complexity of precluding an alternative"
    - "guarantees for the success frequency of an algorithm for finding dodgson election winners"
    - "how many candidates are needed to make elections hard to manipulate"
    - "complexity of manipulating elections with few candidates"
    - "exact complexity of the winner problem for young elections"
    - "exact analysis of dodgson elections lewis carroll s 1876 voting system is complete for parallel access to np"

Connected through hyperedge HE-4 (induced by source paper "complexity of the exact domatic number problem and of the exact conveyor flow shop problem"):
  with members:
    - "recognizing when heuristics can approximate minimum vertex covers is complete for parallel access to np"
    - "exact complexity of the winner problem for young elections"
    - "exact complexity of exact four colorability"
    - "unambiguous computation boolean hierarchies and sparse turing complete sets"
    - "exact analysis of dodgson elections lewis carroll s 1876 voting system is complete for parallel access to np"

Connected through hyperedge HE-5 (induced by source paper "recognizing when heuristics can approximate minimum vertex covers is complete for parallel access to np"):
  with members:
    - "complexity of the exact domatic number problem and of the exact conveyor flow shop problem"
    - "exact complexity of the winner problem for young elections"
    - "exact analysis of dodgson elections lewis carroll s 1876 voting system is complete for parallel access to np"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.CC(Computational Complexity)