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: "traversing grammar compressed trees with constant delay"
  Abstract: A grammar-compressed ranked tree is represented with a linear space overhead so that a single traversal step, i.e., the move to the parent or the i-th child, can be carried out in constant time. Moreover, we extend our data structure such that equality of subtrees can be checked in constant time.

Connected through hyperedge HE-1 (induced by source paper "grammar based graph compression"):
  with members:
    - "a succinct data structure for self indexing ternary relations"
    - "compressed tree canonization"
    - "recompression a simple and powerful technique for word equations"
    - "fast and tiny structural self indexes for xml"
    - "structure induction by lossless graph compression"
    - "approximation algorithms for pspace hard hierarchically and periodically specified problems"
    - "identifying hierarchical structure in sequences a linear time algorithm"

Connected through hyperedge HE-2 (induced by source paper "fast label extraction in the cdawg"):
  with members:
    - "representing the suffix tree with the cdawg"
    - "linear size cdawg new repetition aware indexing and grammar compression"
    - "composite repetition aware data structures"
    - "large alphabets and incompressibility"

Connected through hyperedge HE-3 (induced by source paper "constructing small tree grammars and small circuits for formulas"):
  with members:
    - "tree compression with top trees revisited"
    - "a really simple approximation of smallest grammar"
    - "a universal grammar based code for lossless compression of binary trees"
    - "tree compression with top trees"
    - "approximation of grammar based compression via recompression"
    - "approximation of smallest linear tree grammar"
    - "grammar based compression in a streaming model"

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)