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: "reducibility among fractional stability problems"
  Abstract: In this paper, we resolve the computational complexity of a number of outstanding open problems with practical applications. Here is the list of problems we show to be PPAD-complete, along with the domains of practical significance: Fractional Stable Paths Problem (FSPP) [21] - Internet routing; Core of Balanced Games [41] - Economics and Game theory; Scarf's Lemma [41] - Combinatorics; Hypergraph Matching [1]- Social Choice and Preference Systems; Fractional Bounded Budget Connection Games (FBBC) [30] - Social networks; and Strong Fractional Kernel [2]- Graph Theory. In fact, we show that no fully polynomial-time approximation schemes exist (unless PPAD is in FP). #R##N#This paper is entirely a series of reductions that build in nontrivial ways on the framework established in previous work. In the course of deriving these reductions, we created two new concepts - preference games and personalized equilibria. The entire set of new reductions can be presented as a lattice with the above problems sandwiched between preference games (at the "easy" end) and personalized equilibria (at the "hard" end). Our completeness results extend to natural approximate versions of most of these problems. On a technical note, we wish to highlight our novel "continuous-to-discrete" reduction from exact personalized equilibria to approximate personalized equilibria using a linear program augmented with an exponential number of "min" constraints of a specific form. In addition to enhancing our repertoire of PPAD-complete problems, we expect the concepts and techniques in this paper to find future use in algorithmic game theory.

Connected through hyperedge HE-1 (induced by source paper "the classes ppa k existence from arguments modulo k"):
  with members:
    - "the hairy ball problem is ppad complete"
    - "the complexity of splitting necklaces and bisecting ham sandwiches"
    - "ppp completeness with connections to cryptography"
    - "unique end of potential line"
    - "consensus halving is ppa complete"
    - "integer factoring and modular square roots"
    - "on the complexity of finding falsifying assignments for herbrand disjunctions"
    - "the complexity of non monotone markets"

Connected through hyperedge HE-2 (induced by source paper "the hairy ball problem is ppad complete"):
  with members:
    - "end of potential line"
    - "the complexity of splitting necklaces and bisecting ham sandwiches"
    - "consensus halving is ppa complete"
    - "on the complexity of envy free cake cutting"
    - "settling the complexity of computing two player nash equilibria"

Connected through hyperedge HE-3 (induced by source paper "cache me if you can capacitated selfish replication games in networks"):
  with members:
    - "approximation algorithm for the binary preference capacitated selfish replication game and a tight bound on its price of anarchy"
    - "optimal data placement on networks with a constant number of clients"
    - "settling the complexity of computing two player nash equilibria"

Connected through hyperedge HE-4 (induced by source paper "ppp completeness with connections to cryptography"):
  with members:
    - "on the polynomial parity argument complexity of the combinatorial nullstellensatz"
    - "consensus halving is ppa complete"
    - "cls new problems and completeness"
    - "a converse to banach s fixed point theorem and its cls completeness"
    - "local max cut in smoothed polynomial time"
    - "integer factoring and modular square roots"
    - "settling the complexity of computing approximate two player nash equilibria"
    - "number balancing is as hard as minkowski s theorem and shortest vector"

Connected through hyperedge HE-5 (induced by source paper "the complexity of splitting necklaces and bisecting ham sandwiches"):
  with members:
    - "end of potential line"
    - "on the polynomial parity argument complexity of the combinatorial nullstellensatz"
    - "computational social choice and computational complexity bffs"
    - "consensus halving is ppa complete"
    - "integer factoring and modular square roots"
    - "hardness results for consensus halving"
    - "settling the complexity of computing approximate two player nash equilibria"
    - "on the complexity of nash equilibria in anonymous games"

Connected through hyperedge HE-6 (induced by source paper "smoothed efficient algorithms and reductions for network coordination games"):
  with members:
    - "improving the smoothed complexity of flip for max cut problems"
    - "near optimal communication lower bounds for approximate nash equilibria"
    - "efficient local search in coordination games on graphs"
    - "settling the complexity of computing approximate two player nash equilibria"
    - "communication complexity of approximate nash equilibria"
    - "the price of anarchy in auctions"
    - "inapproximability of nash equilibrium"
    - "constant rank bimatrix games are ppad hard"

Connected through hyperedge HE-7 (induced by source paper "consensus halving is ppa complete"):
  with members:
    - "on the polynomial parity argument complexity of the combinatorial nullstellensatz"
    - "computational social choice and computational complexity bffs"
    - "integer factoring and modular square roots"
    - "hardness results for consensus halving"
    - "settling the complexity of computing approximate two player nash equilibria"
    - "on the complexity of nash equilibria in anonymous games"
    - "inapproximability of nash equilibrium"
    - "on the complexity of finding falsifying assignments for herbrand disjunctions"

Connected through hyperedge HE-8 (induced by source paper "constant rank bimatrix games are ppad hard"):
  with members:
    - "settling some open problems on 2 player symmetric nash equilibria"
    - "a direct reduction of ppad lemke verified linear complementarity problems to bimatrix games"
    - "on oblivious ptas s for nash equilibrium"
    - "bilinear games polynomial time algorithms for rank based subclasses"
    - "the complexity of the homotopy method equilibrium selection and lemke howson solutions"
    - "settling the complexity of arrow debreu equilibria in markets with additively separable utilities"
    - "settling the complexity of computing two player nash equilibria"
    - "games of fixed rank a hierarchy of bimatrix games"

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)