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: "three coloring graphs with no induced seven vertex path ii using a triangle"
  Abstract: In this paper, we give a polynomial time algorithm which determines if a given graph containing a triangle and no induced seven-vertex path is 3-colorable, and gives an explicit coloring if one exists. In previous work, we gave a polynomial time algorithm for three-coloring triangle-free graphs with no induced seven-vertex path. Combined, our work shows that three-coloring a graph with no induced seven-vertex path can be done in polynomial time.

Connected through hyperedge HE-1 (induced by source paper "a survey on the computational complexity of colouring graphs with forbidden subgraphs"):
  with members:
    - "bounding the clique width of h free chordal graphs"
    - "the coloring problem for p 5 p 5 free graphs and p 5 k p e free graphs is polynomial"
    - "bounding clique width via perfect graphs"
    - "clique width of graph classes defined by two forbidden induced subgraphs"
    - "narrowing the complexity gap for colouring c_s p_t free graphs"
    - "4 coloring p_6 free graphs with no induced 5 cycles"
    - "polynomial time algorithms for minimum weighted colorings of p_5 bar p _5 free graphs and related graph classes"
    - "complexity of coloring graphs without paths and cycles"

Connected through hyperedge HE-2 (induced by source paper "complexity of coloring graphs without paths and cycles"):
  with members:
    - "a certifying algorithm for 3 colorability of p5 free graphs"

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)