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: "approximation hardness of graphic tsp on cubic graphs"
  Abstract: We prove explicit approximation hardness results for the Graphic TSP on cubic and subcubic graphs as well as the new inapproximability bounds for the corresponding instances of the (1,2)-TSP. The proof technique uses new modular constructions of simulating gadgets for the restricted cubic and subcubic instances. The modular constructions used in the paper could be also of independent interest.

Connected through hyperedge HE-1 (induced by source paper "beating the integrality ratio for s t tours in graphs"):
  with members:
    - "a 1 5 approximation for path tsp"
    - "an improved upper bound on the integrality ratio for the s t path tsp"
    - "a constant factor approximation algorithm for the asymmetric traveling salesman problem"
    - "approaching frac 3 2 for the s t path tsp"
    - "improving christofides algorithm for the s t path tsp"

Connected through hyperedge HE-2 (induced by source paper "graphic tsp in cubic graphs"):
  with members:
    - "new inapproximability bounds for tsp"
    - "improved inapproximability for tsp"
    - "approximating graphic tsp by matchings"
    - "the traveling salesman problem on cubic and subcubic graphs"
    - "13 9 approximation for graphic tsp"

Connected through hyperedge HE-3 (induced by source paper "tsp tours in cubic graphs beyond 4 3"):
  with members:
    - "eight fifth approximation for the path tsp"
    - "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 4 3 approximation for tsp on cubic 3 edge connected graphs"
    - "a proof of the boyd carr conjecture"

Connected through hyperedge HE-4 (induced by source paper "new inapproximability bounds for tsp"):
  with members:
    - "on approximation lower bounds for tsp with bounded metrics"
    - "improved inapproximability for tsp"
    - "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.CC(Computational Complexity)