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: "a 2 542 approximation for precedence constrained single machine scheduling with release dates and total weighted completion time objective"
  Abstract: We present a $\sqrt{e}/(\sqrt{e}-1)$-approximation algorithm for the nonpreemptive scheduling problem to minimize the total weighted completion time of jobs on a single machine subject to release dates and precedence constraints. The previously best known approximation algorithm dates back to 1997; its performance guarantee can be made arbitrarily close to the Euler constant $e$.

Connected through hyperedge HE-1 (induced by source paper "a note on the asymptotic optimality of work conserving disciplines in completion time minimization"):
  with members:
    - "scheduling to minimize total weighted completion time via time indexed linear programming relaxations"
    - "better unrelated machine scheduling for weighted completion time via random offsets from non uniform distributions"
    - "lift and round to improve weighted completion time on unrelated machines"

Connected through hyperedge HE-2 (induced by source paper "generalizing the kawaguchi kyan bound to stochastic parallel machine scheduling"):
  with members:
    - "stochastic online scheduling on unrelated machines"
    - "unrelated machine scheduling of jobs with uniform smith ratios"

Connected through hyperedge HE-3 (induced by source paper "scheduling to minimize total weighted completion time via time indexed linear programming relaxations"):
  with members:
    - "better unrelated machine scheduling for weighted completion time via random offsets from non uniform distributions"
    - "on the configuration lp of the restricted assignment problem"
    - "lift and round to improve weighted completion time on unrelated machines"
    - "a 1 epsilon approximation for makespan scheduling with precedence constraints using lp hierarchies"
    - "towards tight lower bounds for scheduling problems"
    - "santa claus schedules jobs on unrelated machines"
    - "the geometry of scheduling"

Connected through hyperedge HE-4 (induced by source paper "a 2 epsilon approximation for precedence constrained single machine scheduling with release dates and total weighted completion time objective"):
  with members:
    - "polynomial time approximation schemes for the traveling repairman and other minimum latency problems"

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)