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: "the stength of weak cooperation a case study on flickr"
  Abstract: Web 2.0 works with the principle of weak cooperation, where a huge amount of individual contributions build solid and structured sources of data. In this paper, we detail the main properties of this weak cooperation by illustrating them on the photo publication website Flickr, showing the variety of uses producing a rich content and the various procedures devised by Flickr users themselves to select quality. We underlined the interaction between small and heavy users as a specific form of collective production in large social networks communities. We also give the main statistics on the (5M-users, 150M-photos) data basis we worked on for this study, collected from Flickr website using the public API.

Connected through hyperedge HE-1 (induced by source paper "the contours of crowd capability"):
  with members:
    - "the new war correspondents the rise of civic media curation in urban warfare"
    - "the theory of crowd capital"
    - "crowdsourcing attention and productivity"

Connected through hyperedge HE-2 (induced by source paper "a framework for policy crowdsourcing"):
  with members:
    - "the contours of crowd capability"
    - "how to work a crowd developing crowd capital through crowdsourcing"
    - "crowdsourcing the policy cycle"
    - "a computational model of crowds for collective intelligence"
    - "the theory of crowd capital"

Connected through hyperedge HE-3 (induced by source paper "self organizing map and social networks unfolding online social popularity"):
  with members:
    - "crowdsourcing attention and productivity"
    - "mapping weblog communities"

Connected through hyperedge HE-4 (induced by source paper "the theory of crowd capital"):
  with members:
    - "the labor economics of paid crowdsourcing"
    - "crowdsourcing attention and productivity"

Connected through hyperedge HE-5 (induced by source paper "internal links and pairs as a new tool for the analysis of bipartite complex networks"):
  with members:
    - "ten weeks in the life of an edonkey server"

Connected through hyperedge HE-6 (induced by source paper "folks in folksonomies social link prediction from shared metadata"):
  with members:
    - "social browsing on flickr"
    - "the structure of collaborative tagging systems"

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)