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: "nash social welfare for indivisible items under separable piecewise linear concave utilities"
  Abstract: Recently Cole and Gkatzelis gave the first constant factor approximation algorithm for the problem of allocating indivisible items to agents, under additive valuations, so as to maximize the Nash Social Welfare. We give constant factor algorithms for a substantial generalization of their problem -- to the case of separable, piecewise-linear concave utility functions. We give two such algorithms, the first using market equilibria and the second using the theory of stable polynomials. #R##N#In AGT, there is a paucity of methods for the design of mechanisms for the allocation of indivisible goods and the result of Cole and Gkatzelis seemed to be taking a major step towards filling this gap. Our result can be seen as another step in this direction.

Connected through hyperedge HE-1 (induced by source paper "efx exists for three agents"):
  with members:
    - "envy freeness up to any item with high nash welfare the virtue of donating items"
    - "approximating nash social welfare under submodular valuations through un matchings"
    - "a little charity guarantees almost envy freeness"
    - "an improved approximation algorithm for maximin shares"
    - "on fair division of indivisible items"
    - "almost envy freeness with general valuations"
    - "approximating the nash social welfare with budget additive valuations"
    - "finding fair and efficient allocations"

Connected through hyperedge HE-2 (induced by source paper "envy freeness up to any item with high nash welfare the virtue of donating items"):
  with members:
    - "comparing approximate relaxations of envy freeness"
    - "on fair division of indivisible items"
    - "approximation algorithms for computing maximin share allocations"
    - "almost envy freeness with general valuations"
    - "approximating the nash social welfare with budget additive valuations"
    - "finding fair and efficient allocations"
    - "a discrete and bounded envy free cake cutting protocol for any number of agents"
    - "convex program duality fisher markets and nash social welfare"

Connected through hyperedge HE-3 (induced by source paper "satiation in fisher markets and approximation of nash social welfare"):
  with members:
    - "near optimal online algorithms and fast approximation algorithms for resource allocation problems"
    - "a strongly polynomial algorithm for linear exchange markets"
    - "approximating the nash social welfare with budget additive valuations"
    - "finding fair and efficient allocations"
    - "convex program duality fisher markets and nash social welfare"
    - "nash social welfare matrix permanent and stable polynomials"
    - "an improved combinatorial polynomial algorithm for the linear arrow debreu market"
    - "apx hardness of maximizing nash social welfare with indivisible items"

Connected through hyperedge HE-4 (induced by source paper "approximating nash social welfare under submodular valuations through un matchings"):
  with members:
    - "on fair division of indivisible items"
    - "a tale of santa claus hypergraphs and matroids"
    - "approximating the nash social welfare with budget additive valuations"
    - "finding fair and efficient allocations"
    - "convex program duality fisher markets and nash social welfare"
    - "nash social welfare matrix permanent and stable polynomials"
    - "apx hardness of maximizing nash social welfare with indivisible items"
    - "combinatorial algorithm for restricted max min fair allocation"

Connected through hyperedge HE-5 (induced by source paper "a little charity guarantees almost envy freeness"):
  with members:
    - "envy freeness up to any item with high nash welfare the virtue of donating items"
    - "an improved approximation algorithm for maximin shares"
    - "almost envy free allocations with connected bundles"
    - "on fair division of indivisible items"
    - "groupwise maximin fair allocation of indivisible goods"
    - "almost envy freeness with general valuations"
    - "approximating the nash social welfare with budget additive valuations"
    - "finding fair and efficient allocations"

Connected through hyperedge HE-6 (induced by source paper "on the existence of pareto efficient and envy free allocations"):
  with members:
    - "near optimal communication lower bounds for approximate nash equilibria"
    - "communication complexity of cake cutting"
    - "almost envy freeness with general valuations"
    - "approximating the nash social welfare with budget additive valuations"
    - "communication complexity of discrete fair division"
    - "convex program duality fisher markets and nash social welfare"
    - "computing equilibria in markets with budget additive utilities"
    - "communication complexity of approximate nash equilibria"

Connected through hyperedge HE-7 (induced by source paper "auction algorithms for market equilibrium with weak gross substitute demands"):
  with members:
    - "on fair division of indivisible items"
    - "finding fair and efficient allocations"
    - "convex program duality fisher markets and nash social welfare"
    - "nash social welfare matrix permanent and stable polynomials"
    - "ascending price algorithms for unknown markets"
    - "convergence of tâtonnement in fisher markets"
    - "tatonnement in ongoing markets of complementary goods"
    - "a combinatorial polynomial algorithm for the linear arrow debreu market"

Connected through hyperedge HE-8 (induced by source paper "greedy algorithms for maximizing nash social welfare"):
  with members:
    - "almost envy freeness with general valuations"
    - "approximating the nash social welfare with budget additive valuations"
    - "finding fair and efficient allocations"
    - "convex program duality fisher markets and nash social welfare"
    - "apx hardness of maximizing nash social welfare with indivisible items"
    - "combinatorial auctions with decreasing marginal utilities"

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.GT(Computer Science and Game Theory)