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: "product mix auctions and tropical geometry"
  Abstract: In a recent and ongoing work, Baldwin and Klemperer explored a connection between tropical geometry and economics. They gave a sufficient condition for the existence of competitive equilibrium in product-mix auctions of indivisible goods. This result, which we call the Unimodularity Theorem, can also be traced back to the work of Danilov, Koshevoy, and Murota. We introduce auction theory for a mathematical audience and give two simple proofs of the Unimodularity Theorem --- one via tropical and discrete geometry and one via integer programming. We also discuss connections to Walrasian economies, stable matching with transferable utilities, the theory of discrete convex analysis, and some open problems on lattice polytopes such as the Oda conjecture.

Connected through hyperedge HE-1 (induced by source paper "on the decision boundaries of deep neural networks a tropical geometry perspective"):
  with members:
    - "on the geometry of adversarial examples"
    - "on decision regions of narrow deep neural networks"
    - "robustness via curvature regularization and vice versa"
    - "the lottery ticket hypothesis finding sparse trainable neural networks"
    - "tropical geometry of deep neural networks"
    - "bert pre training of deep bidirectional transformers for language understanding"
    - "on the decision boundary of deep neural networks"
    - "structured adversarial attack towards general implementation and better interpretability"

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)