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: "exact counting of euler tours for generalized series parallel graphs"
  Abstract: We give a simple polynomial-time algorithm to exactly count the number of Euler Tours (ETs) of any Eulerian generalized series-parallel graph, and show how to adapt this algorithm to exactly sample a random ET of the given generalized series-parallel graph. Note that the class of generalized seriesparallel graphs includes all outerplanar graphs. We can perform the counting in time $O(m\Delta^3)$, where $\Delta$ is the maximum degree of the graph with $m$ edges. We use $O(m\Delta^2 \log \Delta)$ bits to store intermediate values during our computations. To date, these are the first known polynomial-time algorithms to count or sample ETs of any class of graphs; there are no other known polynomial-time algorithms to even approximately count or sample ETs of any other class of graphs. The problem of counting ETs is known to be $#P$-complete for general graphs (Brightwell and Winkler, 2005 [3]) and also for planar graphs (Creed, 2009 [4]).

Connected through hyperedge HE-1 (induced by source paper "an efficient algorithm for mixed domination on generalized series parallel graphs"):
  with members:
    - "on fixed parameter tractability of the mixed domination problem for graphs with bounded tree width"

Connected through hyperedge HE-2 (induced by source paper "counting euler tours in undirected bounded treewidth graphs"):
  with members:
    - "exact counting of euler tours for graphs of bounded treewidth"
    - "the complexity of counting eulerian tours in 4 regular graphs"
    - "log space algorithms for paths and matchings in k trees"
    - "on the expressive power of permanents and perfect matchings of matrices of bounded pathwidth cliquewidth"

Connected through hyperedge HE-3 (induced by source paper "bounded treewidth and space efficient linear algebra"):
  with members:
    - "exact counting of euler tours for graphs of bounded treewidth"
    - "log space algorithms for paths and matchings in k trees"

Connected through hyperedge HE-4 (induced by source paper "tree width and logspace determinants and counting euler tours"):
  with members:
    - "exact counting of euler tours for graphs of bounded treewidth"

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.DS(Data Structures and Algorithms)