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: "peeling the grid"
  Abstract: Consider the set of points formed by the integer $n\times n$ grid and the process that in each iteration removes from the point set the vertices of its convex hull. Here, we prove that the number of iterations of this process is $O\!\left(n^{4/3}\right)$; that is, the number of convex layers of the $n\times n$ grid is $\Theta\!\left(n^{4/3}\right)$.

Connected through hyperedge HE-1 (induced by source paper "homotopic curve shortening and the affine curve shortening flow"):
  with members:
    - "crossing minimization in perturbed drawings"
    - "recognizing weak embeddings of graphs"
    - "grid peeling and the affine curve shortening flow"
    - "computing homotopic shortest paths efficiently"

Connected through hyperedge HE-2 (induced by source paper "on separating points by lines"):
  with members:
    - "on range searching with semialgebraic sets ii"
    - "on the expected complexity of random convex hulls"

Connected through hyperedge HE-3 (induced by source paper "grid peeling and the affine curve shortening flow"):
  with members:
    - "a simple convex layers algorithm"

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.DM(Discrete Mathematics)