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: "efficient constructions of convex combinations for 2 edge connected subgraphs on fundamental classes"
  Abstract: Finding the exact integrality gap $\alpha$ for the LP relaxation of the 2-edge-connected spanning multigraph problem (2EC) is closely related to the same problem for the Held-Karp relaxation of the metric traveling salesman problem (TSP). While the former problem seems easier than the latter, since it is less constrained, currently the upper bounds on the respective integrality gaps for the two problems are the same. #R##N#An approach to proving integrality gaps for both of these problems is to consider fundamental classes of extreme points. For 2EC, better bounds on the integrality gap are known for certain important special cases of these fundamental points. For example, for half-integer square points, the integrality gap is between $\frac{6}{5}$ and $\frac{4}{3}$. Our main result is to improve the approximation factor to $\frac{9}{7}$ for 2EC for these points. Our approach is based on constructing convex combinations and our key tool is the top-down coloring framework for tree augmentation, whose flexibility we employ to exploit beneficial properties in both the initial spanning tree and in the input graph. We also show how these tools can be tailored to the closely related problem of uniform covers for which the proofs of the best-known bounds do not yield polynomial-time algorithms. Another key ingredient is to use a rainbow spanning tree decomposition, which allows us to obtain a convex combination of spanning trees with particular properties

Connected through hyperedge HE-1 (induced by source paper "towards improving christofides algorithm for half integer tsp"):
  with members:
    - "the salesman s improved tours for fundamental classes"
    - "shorter tours and longer detours uniform covers and a bit beyond"

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.DM(Discrete Mathematics)