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 altmetric performance of publications authored by brazilian researchers analysis of cnpq productivity scholarship holders"
  Abstract: The present work seeks to analyse the altmetric performance of Brazilian publications authored by researchers who are productivity scholarship holders (PQ) of the National Council of Scientific and Technological Development (CNPq). It was considered, within the scope of this research, the PQs in activity in October, 2017 (n = 14.609). The scientific production registered on Lattes was collected via GetLattesData and filtered by articles from academic journals published between 2016 and October 2017 that hold the Digital Object Identifier (n = 99064). The online attention data are analysed according to their distribution by density and variation; language of the publication and field of knowledge; and by average performance of the type of source that has provided its altmetric values. The density evidences the long tail behavior of the variable, with most part of the articles with altmetrics score = 0, while few articles have a high index. The average of the online attention indicates a better performance of articles written in English and belonging to the Health and Biological Sciences field of knowledge. As for the sources, there was a good performance from Mendeley, followed by Twitter and a low coverage from Facebook

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.DL(Digital Libraries)