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: "a digital preservation appliance based on openbsd"
  Abstract: The LOCKSS program has developed and deployed in a world-wide test a system for preserving access to academic journals published on the Web. The fundamental problem for any digital preservation system is that it must be affordable for the long term. To reduce the cost of ownership, the LOCKSS system uses generic PC hardware, open source software, and peer-to-peer technology. It is packaged as a ``network appliance'', a single-function box that can be connected to the Internet, configured and left alone to do its job with minimal monitoring or administration. The first version of this system was based on a Linux boot floppy. After three years of testing it was replaced by a second version, based on OpenBSD and booting from CD-ROM. #R##N#We focus in this paper on the design, implementation and deployment of a network appliance based on an open source operating system. We provide an overview of the LOCKSS application and describe the experience of deploying and supporting its first version. We list the requirements we took from this to drive the design of the second version, describe how we satisfied them in the OpenBSD environment, and report on the initial

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.DC(Distributed, Parallel, and Cluster Computing)