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: "feedback vertex sets in tournaments"
  Abstract: We study combinatorial and algorithmic questions around minimal feedback vertex sets in tournament graphs. #R##N#On the combinatorial side, we derive strong upper and lower bounds on the maximum number of minimal feedback vertex sets in an n-vertex tournament. We prove that every tournament on n vertices has at most 1.6740^n minimal feedback vertex sets, and that there is an infinite family of tournaments, all having at least 1.5448^n minimal feedback vertex sets. This improves and extends the bounds of Moon (1971). #R##N#On the algorithmic side, we design the first polynomial space algorithm that enumerates the minimal feedback vertex sets of a tournament with polynomial delay. The combination of our results yields the fastest known algorithm for finding a minimum size feedback vertex set in a tournament.

Connected through hyperedge HE-1 (induced by source paper "a 2 approximation algorithm for feedback vertex set in tournaments"):
  with members:
    - "faster exact and parameterized algorithm for feedback vertex set in tournaments"
    - "hardness of vertex deletion and project scheduling"

Connected through hyperedge HE-2 (induced by source paper "enumeration and maximum number of minimal connected vertex covers in graphs"):
  with members:
    - "deterministic parameterized connected vertex cover"
    - "finding induced subgraphs via minimal triangulations"

Connected through hyperedge HE-3 (induced by source paper "exact algorithms via monotone local search"):
  with members:
    - "exact algorithms for maximum independent set"
    - "faster algorithms to enumerate hypergraph transversals"
    - "a faster fpt algorithm and a smaller kernel for block graph vertex deletion"
    - "faster exact and parameterized algorithm for feedback vertex set in tournaments"
    - "on feedback vertex set new measure and new structures"
    - "an fpt algorithm and a polynomial kernel for linear rankwidth 1 vertex deletion"
    - "unit interval editing is fixed parameter tractable"
    - "linear recognition of almost interval graphs"

Connected through hyperedge HE-4 (induced by source paper "faster exact and parameterized algorithm for feedback vertex set in tournaments"):
  with members:
    - "solving connectivity problems parameterized by treewidth in single exponential time"

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.DM(Discrete Mathematics)