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: "kernelizations for the hybridization number problem on multiple nonbinary trees"
  Abstract: Given a finite set $X$, a collection $\mathcal{T}$ of rooted phylogenetic trees on $X$ and an integer $k$, the Hybridization Number problem asks if there exists a phylogenetic network on $X$ that displays all trees from $\mathcal{T}$ and has reticulation number at most $k$. We show two kernelization algorithms for Hybridization Number, with kernel sizes $4k(5k)^t$ and $20k^2(\Delta^+-1)$ respectively, with $t$ the number of input trees and $\Delta^+$ their maximum outdegree. Experiments on simulated data demonstrate the practical relevance of these kernelization algorithms. In addition, we present an $n^{f(k)}t$-time algorithm, with $n=|X|$ and $f$ some computable function of $k$.

Connected through hyperedge HE-1 (induced by source paper "a practical fixed parameter algorithm for constructing tree child networks from multiple binary trees"):
  with members:
    - "hybridization number on three rooted binary trees is ept"

Connected through hyperedge HE-2 (induced by source paper "a tight kernel for computing the tree bisection and reconnection distance between two phylogenetic trees"):
  with members:
    - "on unrooted and root uncertain variants of several well known phylogenetic network problems"
    - "calculating the unrooted subtree prune and regraft distance"
    - "hybridization number on three rooted binary trees is ept"
    - "kernelization lower bounds by cross composition"
    - "constructing minimal phylogenetic networks from softwired clusters is fixed parameter tractable"

Connected through hyperedge HE-3 (induced by source paper "treewidth distance on phylogenetic trees"):
  with members:
    - "on unrooted and root uncertain variants of several well known phylogenetic network problems"
    - "efficient fpt algorithms for strict compatibility of unrooted phylogenetic trees"
    - "calculating the unrooted subtree prune and regraft distance"
    - "a complete anytime algorithm for treewidth"
    - "graph triangulations and the compatibility of unrooted phylogenetic trees"

Connected through hyperedge HE-4 (induced by source paper "on unrooted and root uncertain variants of several well known phylogenetic network problems"):
  with members:
    - "constructing minimal phylogenetic networks from softwired clusters is fixed parameter tractable"

Connected through hyperedge HE-5 (induced by source paper "hybridization number on three trees"):
  with members:
    - "constructing minimal phylogenetic networks from softwired clusters is fixed parameter tractable"

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)