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: "atomic services sustainable ecosystem of smart city services through pan european collaboration"
  Abstract: In a world with an ever increasing urbanization, governance is investigating innovative solutions to sustain the society evolution. Internet-of-Things promises huge benefits for cities and the proliferation of smart city deployments demonstrates the common acceptance of IoT as basis for many solutions. The city pilots developments occurred in parallel and with different designs thus creating fragmentation of IoT. The European project SynchroniCity aims to synchronize 8 smart cities to establish a shared environment fostering a self-sustained business growth. In this article we present the collaborative methodology and shared efforts spent towards the creation of a common ecosystem for the development of smart city services. Our design evolves around the concept of ”atomic services” that implements a single functional block to be composed for full-fledged smart city services. This creates opportunities for diverse stakeholders to participate to a global smart cities market. The methodology and outcome of our efforts will be followed by 10 new cities globally, thus expanding the market range for IoT stakeholders.

Connected through hyperedge HE-1 (induced by source paper "smart city iot services creation through large scale collaboration"):
  with members:
    - "semantic gateway as a service architecture for iot interoperability"

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.CY(Computers and Society)