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 4 3 approximation for tsp on cubic 3 edge connected graphs"
  Abstract: We provide a polynomial time 4/3 approximation algorithm for TSP on metrics arising from the metric completion of cubic 3-edge connected graphs.

Connected through hyperedge HE-1 (induced by source paper "graph tsp from steiner cycles"):
  with members:
    - "eight fifth approximation for the path tsp"
    - "shorter tours by nicer ears 7 5 approximation for graphic tsp 3 2 for the path version and 4 3 for two edge connected subgraphs"
    - "approximating graphic tsp by matchings"
    - "13 9 approximation for graphic tsp"

Connected through hyperedge HE-2 (induced by source paper "tsp tours in cubic graphs beyond 4 3"):
  with members:
    - "eight fifth approximation for the path tsp"
    - "approximation hardness of graphic tsp on cubic graphs"
    - "a 9 7 approximation algorithm for graphic tsp in cubic bipartite graphs"
    - "improved inapproximability for tsp"
    - "on the integrality gap of the subtour lp for the 1 2 tsp"
    - "improving christofides algorithm for the s t path tsp"
    - "approximating graphic tsp by matchings"
    - "a proof of the boyd carr conjecture"

Connected through hyperedge HE-3 (induced by source paper "a 9 7 approximation algorithm for graphic tsp in cubic bipartite graphs"):
  with members:
    - "improved approximations for cubic and cubic bipartite tsp"
    - "an improved analysis of the m omke svensson algorithm for graph tsp on subquartic graphs"
    - "tsp tours in cubic graphs beyond 4 3"
    - "shorter tours by nicer ears 7 5 approximation for graphic tsp 3 2 for the path version and 4 3 for two edge connected subgraphs"
    - "approximating graphic tsp by matchings"
    - "the traveling salesman problem on cubic and subcubic graphs"

Connected through hyperedge HE-4 (induced by source paper "on the integrality gap of the subtour lp for the 1 2 tsp"):
  with members:
    - "improved integrality gap upper bounds for tsp with distances one and two"
    - "practical graph isomorphism ii"
    - "shorter tours by nicer ears 7 5 approximation for graphic tsp 3 2 for the path version and 4 3 for two edge connected subgraphs"
    - "approximating graphic tsp by matchings"
    - "a proof of the boyd carr conjecture"
    - "the traveling salesman problem on cubic and subcubic graphs"
    - "13 9 approximation for graphic tsp"

Connected through hyperedge HE-5 (induced by source paper "the traveling salesman problem on cubic and subcubic graphs"):
  with members:
    - "tsp tours in cubic graphs beyond 4 3"
    - "shorter tours by nicer ears 7 5 approximation for graphic tsp 3 2 for the path version and 4 3 for two edge connected subgraphs"
    - "approximating graphic tsp by matchings"
    - "13 9 approximation for graphic tsp"

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)