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: "the complexity of rooted phylogeny problems"
  Abstract: Several computational problems in phylogenetic reconstruction can be#N#formulated as restrictions of the following general problem: given a formula in#N#conjunctive normal form where the literals are rooted triples, is there a#N#rooted binary tree that satisfies the formula? If the formulas do not contain#N#disjunctions, the problem becomes the famous rooted triple consistency problem,#N#which can be solved in polynomial time by an algorithm of Aho, Sagiv,#N#Szymanski, and Ullman. If the clauses in the formulas are restricted to#N#disjunctions of negated triples, Ng, Steel, and Wormald showed that the problem#N#remains NP-complete. We systematically study the computational complexity of#N#the problem for all such restrictions of the clauses in the input formula. For#N#certain restricted disjunctions of triples we present an algorithm that has#N#sub-quadratic running time and is asymptotically as fast as the fastest known#N#algorithm for the rooted triple consistency problem. We also show that any#N#restriction of the general rooted phylogeny problem that does not fall into our#N#tractable class is NP-complete, using known results about the complexity of#N#Boolean constraint satisfaction problems. Finally, we present a pebble game#N#argument that shows that the rooted triple consistency problem (and also all#N#generalizations studied in this paper) cannot be solved by Datalog.

Connected through hyperedge HE-1 (induced by source paper "the complexity of surjective homomorphism problems a survey"):
  with members:
    - "finding vertex surjective graph homomorphisms"
    - "approximation for maximum surjective constraint satisfaction problems"
    - "the complexity of global cardinality constraints"
    - "the stubborn problem is stubborn no more a polynomial algorithm for 3 compatible colouring and the stubborn list partition problem"
    - "orthomodular lattices foulis semigroups and dagger kernel categories"
    - "the approximability of three valued max csp"

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.CC(Computational Complexity)