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 "recognizing optimal 1 planar graphs in linear time"):
  Abstract: A graph with n vertices is 1-planar if it can be drawn in the plane such that each edge is crossed at most once, and is optimal if it has the maximum of \(4n-8\) edges. We show that optimal 1-planar graphs can be recognized in linear time. Our algorithm implements a graph reduction system with two rules, which can be used to reduce every optimal 1-planar graph to an irreducible extended wheel graph. The graph reduction system is non-deterministic, constraint, and non-confluent.

Includes members:
  Member "parameterized complexity of 1 planarity":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "an experimental study of a 1 planarity testing and embedding algorithm")
  Member "a reduction system for optimal 1 planar graphs":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "recognizing ic planar and nic planar graphs")
  Member "recognizing and drawing ic planar graphs":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "fan crossing free graphs")
  Member "on 4 map graphs and 1 planar graphs and their recognition problem":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "t shape visibility representations of 1 planar graphs")
  Member "on the recognition of fan planar and maximal outer fan planar graphs":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "fan crossing free graphs")
  Member "adding one edge to planar graphs makes crossing number and 1 planarity hard":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "an experimental study of a 1 planarity testing and embedding algorithm")
  Member "the straight line rac drawing problem is np hard":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "rac drawings in subcubic area")

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)