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: "weighted efficient domination for p_6 free graphs in polynomial time"
  Abstract: In a finite undirected graph $G=(V,E)$, a vertex $v \in V$ {\em dominates} itself and its neighbors in $G$. A vertex set $D \subseteq V$ is an {\em efficient dominating set} ({\em e.d.} for short) of $G$ if every $v \in V$ is dominated in $G$ by exactly one vertex of $D$. The {\em Efficient Domination} (ED) problem, which asks for the existence of an e.d. in $G$, is known to be NP-complete for $P_7$-free graphs but solvable in polynomial time for $P_5$-free graphs. The $P_6$-free case was the last open question for the complexity of ED on $F$-free graphs. #R##N#Recently, Lokshtanov, Pilipczuk and van Leeuwen showed that weighted ED is solvable in polynomial time for $P_6$-free graphs, based on their sub-exponential algorithm for the Maximum Weight Independent Set problem for $P_6$-free graphs. Independently, at the same time, Mosca found a polynomial time algorithm for weighted ED on $P_6$-free graphs using a direct approach. In this paper, we describe the details of this approach which is simpler and much faster, namely its time bound is ${\cal O}(n^6 m)$.

Connected through hyperedge HE-1 (induced by source paper "on efficient domination for some classes of h free chordal graphs"):
  with members:
    - "polynomial time algorithms for weighted efficient domination problems in at free graphs and dually chordal graphs"
    - "bounding the clique width of h free chordal graphs"
    - "efficient domination for some subclasses of p_6 free graphs in polynomial time"
    - "weighted efficient domination for p_5 kp_2 free graphs in polynomial time"
    - "new polynomial cases of the weighted efficient domination problem"
    - "efficient dominating and edge dominating sets for graphs and hypergraphs"
    - "algorithms for unipolar and generalized split 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)