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 "packing coloring of undirected and oriented generalized theta graphs"):
  Abstract: The packing chromatic number $\chi$ $\rho$ (G) of an undirected (resp. oriented) graph G is the smallest integer k such that its set of vertices V (G) can be partitioned into k disjoint subsets V 1,..., V k, in such a way that every two distinct vertices in V i are at distance (resp. directed distance) greater than i in G for every i, 1 $\le$ i $\le$ k. The generalized theta graph $\Theta$ {\ell} 1,...,{\ell}p consists in two end-vertices joined by p $\ge$ 2 internally vertex-disjoint paths with respective lengths 1 $\le$ {\ell} 1 $\le$ . . . $\le$ {\ell} p. We prove that the packing chromatic number of any undirected generalized theta graph lies between 3 and max{5, n 3 + 2}, where n 3 = |{i / 1 $\le$ i $\le$ p, {\ell} i = 3}|, and that both these bounds are tight. We then characterize undirected generalized theta graphs with packing chromatic number k for every k $\ge$ 3. We also prove that the packing chromatic number of any oriented generalized theta graph lies between 2 and 5 and that both these bounds are tight.

Includes members:
  Member "on packing colorings of distance graphs":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "on packing chromatic number of subcubic outerplanar graphs")
  Member "dichotomies properties on computational complexity of s packing coloring problems":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "spectrum graph coloring to improve wi fi channel assignment in a real world scenario via edge contraction")
  Member "packing chromatic number of distance graphs":
    also connected through other hyperedges:
      (none)
  Member "the packing chromatic number of the square lattice is at least 12":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "on packing chromatic number of subcubic outerplanar graphs")

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)