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: "a discrete and bounded envy free cake cutting protocol for four agents"
  Abstract: We consider the well-studied cake cutting problem in which the goal is to identify a fair allocation based on a minimal number of queries from the agents. The problem has attracted considerable attention within various branches of computer science, mathematics, and economics. Although, the elegant Selfridge-Conway envy-free protocol for three agents has been known since 1960, it has been a major open problem for the last fifty years to obtain a bounded envy-free protocol for more than three agents. We propose a discrete and bounded envy-free protocol for four agents.

Connected through hyperedge HE-1 (induced by source paper "consenus halving does it ever get easier"):
  with members:
    - "the hairy ball problem is ppad complete"
    - "computing exact solutions of consensus halving and the borsuk ulam theorem"
    - "on the complexity of modulo q arguments and the chevalley warning theorem"
    - "fair and efficient cake division with connected pieces"
    - "the classes ppa k existence from arguments modulo k"
    - "the complexity of splitting necklaces and bisecting ham sandwiches"
    - "consensus halving is ppa complete"
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"

Connected through hyperedge HE-2 (induced by source paper "computing exact solutions of consensus halving and the borsuk ulam theorem"):
  with members:
    - "approximating the existential theory of the reals"
    - "the complexity of splitting necklaces and bisecting ham sandwiches"
    - "an improved envy free cake cutting protocol for four agents"
    - "consensus halving is ppa complete"
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"
    - "hardness results for consensus halving"
    - "recognition and complexity of point visibility graphs"
    - "inapproximability of nash equilibrium"

Connected through hyperedge HE-3 (induced by source paper "fair division of mixed divisible and indivisible goods"):
  with members:
    - "efx exists for three agents"
    - "an improved approximation algorithm for maximin shares"
    - "monotonicity and competitive equilibrium in cake cutting"
    - "truthful fair division without free disposal"
    - "approximation algorithms for computing maximin share allocations"
    - "almost envy freeness with general valuations"
    - "the query complexity of cake cutting"
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"

Connected through hyperedge HE-4 (induced by source paper "cake cutting on graphs a discrete and bounded proportional protocol"):
  with members:
    - "an improved envy free cake cutting protocol for four agents"
    - "networked fairness in cake cutting"
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"
    - "fair division via social comparison"

Connected through hyperedge HE-5 (induced by source paper "truthful fair division without free disposal"):
  with members:
    - "on the complexity of chore division"
    - "deterministic strategyproof and fair cake cutting"
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"
    - "cake cutting algorithms for piecewise constant and piecewise uniform valuations"
    - "incentive compatible two player cake cutting"
    - "truthful fair division"

Connected through hyperedge HE-6 (induced by source paper "fair allocation of indivisible public goods"):
  with members:
    - "fair knapsack"
    - "almost envy freeness with general valuations"
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"
    - "the core of the participatory budgeting problem"
    - "proportional justified representation"
    - "justified representation in approval based committee voting"

Connected through hyperedge HE-7 (induced by source paper "an improved envy free cake cutting protocol for four agents"):
  with members:
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"
    - "waste makes haste bounded time algorithms for envy free cake cutting with free disposal"
    - "cake cutting algorithms for piecewise constant and piecewise uniform valuations"

Connected through hyperedge HE-8 (induced by source paper "approximation algorithms for computing maximin share allocations"):
  with members:
    - "truthful allocation mechanisms without payments characterization and implications on fairness"
    - "on truthful mechanisms for maximin share allocations"

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.DS(Data Structures and Algorithms)