human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "relations on words"):
  Abstract: In the first part of this survey, we present classical notions arising in combinatorics on words: growth function of a language, complexity function of an infinite word, pattern avoidance, periodicity and uniform recurrence. Our presentation tries to set up a unified framework with respect to a given binary relation. #R##N#In the second part, we mainly focus on abelian equivalence, $k$-abelian equivalence, combinatorial coefficients and associated relations, Parikh matrices and $M$-equivalence. In particular, some new refinements of abelian equivalence are introduced.

Includes members:
  Member "on the index of simon s congruence for piecewise testability":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "scattered factor universality of words")
  Member "testing k binomial equivalence":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "computing the k binomial complexity of the thue morse word")
  Member "a new approach to the 2 regularity of the ell abelian complexity of 2 automatic sequences":
    also connected through other hyperedges:
      (none)
  Member "avoiding 2 binomial squares and cubes":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "every nonnegative real number is an abelian critical exponent")
  Member "fixed points avoiding abelian k powers":
    also connected through other hyperedges:
      (none)
  Member "avoiding three consecutive blocks of the same size and same sum":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "ten conferences words open problems and conjectures")
  Member "on the complexity of the equivalence problem for probabilistic automata":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "bisimulation equivalence of first order grammars")

Question: Please tell me which class the source paper 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.FL(Formal Languages and Automata Theory)