human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "reassembling trees for the traveling salesman"):
  Abstract: Many recent approximation algorithms for different variants of the traveling salesman problem (asymmetric TSP, graph TSP, s-t-path TSP) exploit the well-known fact that a solution of the natural linear programming relaxation can be written as convex combination of spanning trees. The main argument then is that randomly sampling a tree from such a distribution and then completing the tree to a tour at minimum cost yields a better approximation guarantee than simply taking a minimum cost spanning tree (as in Christofides' algorithm). We argue that an additional step can help: reassembling the spanning trees before sampling. Exchanging two edges in a pair of spanning trees can improve their properties under certain conditions. We demonstrate the usefulness for the metric s-t-path TSP by devising a deterministic polynomial-time algorithm that improves on Seb\H{o}'s previously best approximation ratio of 8/5.

Includes members:
  Member "an experimental evaluation of the best of many christofides algorithm for the traveling salesman problem":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "fast approximations for metric tsp via linear programming")
  Member "better s t tours by gao trees":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "reducing path tsp to tsp")
  Member "on the metric s t path traveling salesman problem":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "a 1 5 approximation for path tsp")
  Member "eight fifth approximation for the path tsp":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "constant factor approximation algorithms for parity constrained facility location problems")
  Member "approximating minimum cost connected t joins":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "constant factor approximation algorithms for parity constrained facility location problems")
  Member "improving christofides algorithm for the s t path tsp":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "reducing path tsp to tsp")
  Member "approximating graphic tsp by matchings":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "simple cubic graphs with no short traveling salesman tour")
  Member "13 9 approximation for graphic tsp":
    also connected through other hyperedges:
      - Hyperedge HE-8 (induced by source paper "reducing path tsp to tsp")

Question: Please tell me which class the source paper 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)