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: "optimum width upward drawings of trees i rooted pathwidth"
  Abstract: An upward drawing of a rooted tree is a drawing such that no parents are below their children. It is ordered if the edges to children appear in prescribed order around each vertex. It is well-known that any tree has an upward (unordered) drawing with width $\log (n+1)$. For ordered drawings, the best-known bounds for the width for binary trees is $O(\log n)$, while for arbitrary trees it is $O(2^{O(\sqrt{\log n})})$. We present algorithms that compute upward drawings with instance-optimal width, i.e., the width is the minimum-possible for the input tree. In this first paper, we mostly study unordered drawings, where the algorithm is very simple and the drawings obtained are straight-line. We also give 2-approximation algorithms for the width of upward ordered drawings, and $O(\Delta)$-approximation where additionally the height is small. In particular any tree has an upward straight-line ordered drawing of area $O(\Delta n\log n)$.

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.CG(Computational Geometry)