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 polynomial time approximation scheme for euclidean steiner forest"
  Abstract: We give a randomized O(n polylog n)-time approximation scheme for the Steiner forest problem in the Euclidean plane. For every fixed eps > 0 and given n terminals in the plane with connection requests between some pairs of terminals, our scheme finds a (1 + eps)-approximation to the minimum-length forest that connects every requested pair of terminals.

Connected through hyperedge HE-1 (induced by source paper "near linear time approximation schemes for steiner tree and forest in low dimensional spaces"):
  with members:
    - "greedy spanners are optimal in doubling metrics"
    - "the greedy spanner is existentially optimal"
    - "a ptas for the steiner forest problem in doubling metrics"
    - "the traveling salesman problem low dimensionality implies a polynomial time approximation scheme"
    - "a light metric spanner"
    - "an efficient polynomial time approximation scheme for steiner forest in planar graphs"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"
    - "fast construction of nets in low dimensional metrics and their applications"

Connected through hyperedge HE-2 (induced by source paper "survivable network design for group connectivity in low treewidth graphs"):
  with members:
    - "sparsest cut on bounded treewidth graphs algorithms and hardness results"
    - "parameters of two prover one round game and the hardness of connectivity problems"
    - "an improved approximation algorithm for the minimum cost subset k connected subgraph problem"
    - "solving connectivity problems parameterized by treewidth in single exponential time"
    - "polynomial time approximation schemes for subset connectivity problems in bounded genus graphs"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"
    - "an o k 3 log n approximation algorithm for vertex connectivity survivable network design"

Connected through hyperedge HE-3 (induced by source paper "polynomial time approximation scheme for minimum k cut in planar and minor free graphs"):
  with members:
    - "minor free graphs have light spanners"
    - "local search yields approximation schemes for k means and k median in euclidean and minor free metrics"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"

Connected through hyperedge HE-4 (induced by source paper "the complexity landscape of fixed parameter directed steiner network problems"):
  with members:
    - "on directed steiner trees with multiple roots"
    - "improved approximation algorithms for budgeted node weighted steiner problems"
    - "euclidean prize collecting steiner forest"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"

Connected through hyperedge HE-5 (induced by source paper "a unified ptas for prize collecting tsp and steiner tree problem in doubling metrics"):
  with members:
    - "a ptas for the steiner forest problem in doubling metrics"
    - "the traveling salesman problem low dimensionality implies a polynomial time approximation scheme"
    - "combining approximation algorithms for the prize collecting tsp"

Connected through hyperedge HE-6 (induced by source paper "a ptas for the steiner forest problem in doubling metrics"):
  with members:
    - "the traveling salesman problem low dimensionality implies a polynomial time approximation scheme"
    - "greedy algorithms for steiner forest"
    - "euclidean prize collecting steiner forest"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"

Connected through hyperedge HE-7 (induced by source paper "an efficient polynomial time approximation scheme for steiner forest in planar graphs"):
  with members:
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"

Connected through hyperedge HE-8 (induced by source paper "euclidean prize collecting steiner forest"):
  with members:
    - "prize collecting network design on planar graphs"
    - "approximation schemes for steiner forest on planar graphs and graphs of bounded treewidth"
    - "product multicommodity flow in wireless networks"
    - "dial a ride from k forest"

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.CG(Computational Geometry)