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 "itemset isomorphism gi hard"):
  Abstract: This paper addresses the problem of finding a class of representative itemsets up to subitemset isomorphism. An efficient algorithm is of practical importance in the domain of optimal sorting networks. Although only exponential algorithms for solving the problem exist in the literature, the complexity classification of the problem has never been addressed. In this paper, we present a complexity classification of the itemset isomorphism and subitemset isomorphism problems. We prove that the problem of checking whether two itemsets are isomorphic to each other is GI-Hard; the Graph Isomorphism (GI) problem is known to be in NP and LWPP, but widely believed to be neither P nor NP-Complete. As an immediate consequence, we prove that finding a class representative itemsets up to subitemset isomorphism is GI-Hard --- at least as hard as the graph isomorphism problem.

Includes members:
  Member "optimal depth sorting networks":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "sorting networks to the end and back again")
  Member "new bounds on optimal sorting networks":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "joint size and depth optimization of sorting networks")
  Member "optimal sorting networks":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "optimal metastability containing sorting via parallel prefix computation")

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.CC(Computational Complexity)