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: "a tree structure for dynamic facility location"
  Abstract: We study the metric facility location problem with client insertions and deletions. This setting differs from the classic dynamic facility location problem, where the set of clients remains the same, but the metric space can change over time. We show a deterministic algorithm that maintains a constant factor approximation to the optimal solution in worst-case time $\tilde O(2^{O(\kappa^2)})$ per client insertion or deletion in metric spaces while answering queries about the cost in $O(1)$ time, where $\kappa$ denotes the doubling dimension of the metric. For metric spaces with bounded doubling dimension, the update time is polylogarithmic in the parameters of the problem.

Connected through hyperedge HE-1 (induced by source paper "the power of recourse better algorithms for facility location in online and dynamic models"):
  with members:
    - "facility location problem in differential privacy model revisited"
    - "online facility location with deletions"
    - "online bipartite matching with amortized o log 2 n replacements"
    - "online and dynamic algorithms for set cover"
    - "efficient construction of probabilistic tree embeddings"
    - "facility location in evolving metrics"
    - "online network design algorithms via hierarchical decompositions"
    - "dynamic facility location via exponential clocks"

Connected through hyperedge HE-2 (induced by source paper "constant factor approximation algorithms for parity constrained facility location problems"):
  with members:
    - "on facility location with general lower bounds"
    - "online facility location with deletions"
    - "optimal parameterized algorithms for planar facility location problems using voronoi diagrams"
    - "facility location in evolving metrics"
    - "lp based algorithms for capacitated facility location"
    - "eight fifth approximation for the path tsp"
    - "local search based approximation algorithms for mobile facility location problems"
    - "fast clustering with lower bounds no customer too far no shop too small"

Connected through hyperedge HE-3 (induced by source paper "fully dynamic k center clustering in doubling metrics"):
  with members:
    - "dynamic low stretch trees via dynamic low diameter decompositions"
    - "fully dynamic hierarchical diameter k clustering and k center"
    - "small space stream summary for matroid center"
    - "expander decomposition and pruning faster stronger and simpler"
    - "dynamic clustering to minimize the sum of radii"
    - "the new data and new challenges in multimedia research"
    - "fast construction of nets in low dimensional metrics and their applications"

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.DS(Data Structures and Algorithms)