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 runs theorem"
  Abstract: We give a new characterization of maximal repetitions (or runs) in strings based on Lyndon words. The characterization leads to a proof of what was known as the “runs” conjecture [R. M. Kolpakov an...

Connected through hyperedge HE-1 (induced by source paper "lyndon words versus inverse lyndon words queries on suffixes and bordered words"):
  with members:
    - "some variations on lyndon words"
    - "inverse lyndon words and inverse lyndon factorizations of words"
    - "on generalized lyndon words"
    - "fsg fast string graph construction for de novo assembly of reads data"
    - "on the size of lempel ziv and lyndon factorizations"
    - "an external memory algorithm for string graph construction"
    - "alternative algorithms for lyndon factorization"
    - "sorting suffixes of a text via its lyndon factorization"

Connected through hyperedge HE-2 (induced by source paper "matching patterns with variables"):
  with members:
    - "graph and string parameters connections between pathwidth cutwidth and the locality number"
    - "quadratic word equations with length constraints counter systems and presburger arithmetic with divisibility"
    - "the hardness of solving simple word equations"
    - "decidability complexity and expressiveness of first order logic over the subword ordering"
    - "detecting one variable patterns"
    - "solutions of word equations over partially commutative structures"
    - "a parameterized study of maximum generalized pattern matching problems"
    - "searching of gapped repeats and subrepetitions in a word"

Connected through hyperedge HE-3 (induced by source paper "inducing the lyndon array"):
  with members:
    - "lyndon array construction during burrows wheeler inversion"
    - "algorithms to compute the lyndon array"
    - "simpler and faster lempel ziv factorization"
    - "inducing the lcp array"

Connected through hyperedge HE-4 (induced by source paper "longest property preserved common factor"):
  with members:
    - "linear time algorithm for long lcf with k mismatches"
    - "indexing weighted sequences neat and efficient"
    - "a hardness result and new algorithm for the longest common palindromic subsequence problem"
    - "sublinear space algorithms for the longest common substring problem"
    - "computing a longest common palindromic subsequence"

Connected through hyperedge HE-5 (induced by source paper "efficient representation and counting of antipower factors in words"):
  with members:
    - "anti powers in infinite words"
    - "algorithms for anti powers in strings"
    - "searching of gapped repeats and subrepetitions in a word"

Connected through hyperedge HE-6 (induced by source paper "on the number of gapped repeats with arbitrary gap"):
  with members:
    - "efficiently finding all maximal alpha gapped repeats"
    - "longest gapped repeats and palindromes"
    - "searching of gapped repeats and subrepetitions in a word"
    - "on primary and secondary repetitions in words"
    - "on the maximal sum of exponents of runs in a string"

Connected through hyperedge HE-7 (induced by source paper "cartesian trees and lyndon trees"):
  with members:
    - "algorithms to compute the lyndon array"
    - "faster longest common extension queries in strings over general alphabets"
    - "near optimal computation of runs over general alphabet via non crossing lce queries"

Connected through hyperedge HE-8 (induced by source paper "prefix frequency of lost positions"):
  with members:
    - "fully bordered words"
    - "beyond the runs theorem"

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)