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: "on replica placement in high availability storage under correlated failure"
  Abstract: A new model describing dependencies among system components as a directed graph is presented and used to solve a novel replica placement problem in data centers. A criterion for optimizing replica placements is formalized and explained. In this work, the optimization goal is to choose placements in which correlated failure events disable as few replicas as possible. A fast optimization algorithm is given for dependency models represented by trees. The main contribution of the paper is an $$On + \rho \log \rho $$On+i¾?logi¾? dynamic programming algorithm for placing $$\rho $$i¾? replicas on a tree with n vertices.

Connected through hyperedge HE-1 (induced by source paper "lexico minimum replica placement in multitrees"):
  with members:
    - "algorithms for optimal replica placement under correlated failure in hierarchical failure domains"
    - "on the complexity of strongly connected components in directed hypergraphs"

Connected through hyperedge HE-2 (induced by source paper "algorithms for optimal replica placement under correlated failure in hierarchical failure domains"):
  with members:
    - "analytical approach to parallel repetition"
    - "optimal replica placement in tree networks with qos and bandwidth constraints and the closest allocation policy"

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)