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: "efficient and reasonable object oriented concurrency"
  Abstract: Making threaded programs safe and easy to reason about is one of the chief difficulties in modern programming. This work provides an efficient execution model for SCOOP, a concurrency approach that provides not only data race freedom but also pre/postcondition reasoning guarantees between threads. The extensions we propose influence both the underlying semantics to increase the amount of concurrent execution that is possible, exclude certain classes of deadlocks, and enable greater performance. These extensions are used as the basis an efficient runtime and optimization pass that improve performance 15x over a baseline implementation. This new implementation of SCOOP is also 2x faster than other well-known safe concurrent languages. The measurements are based on both coordination-intensive and data-manipulation-intensive benchmarks designed to offer a mixture of workloads.

Connected through hyperedge HE-1 (induced by source paper "a semantics comparison workbench for a concurrent asynchronous distributed programming language"):
  with members:
    - "an interference free programming model for network objects"
    - "a graph based semantics workbench for concurrent asynchronous programs"
    - "on the verification of scoop programs"
    - "towards practical graph based verification for an object oriented concurrency model"
    - "verifying monadic second order properties of graph programs"
    - "the design of gp 2"

Connected through hyperedge HE-2 (induced by source paper "an interference free programming model for network objects"):
  with members:
    - "a graph based semantics workbench for concurrent asynchronous programs"
    - "design of an empirical study for comparing the usability of concurrent programming languages"
    - "handling parallelism in a concurrency model"

Connected through hyperedge HE-3 (induced by source paper "a graph based semantics workbench for concurrent asynchronous programs"):
  with members:
    - "towards practical graph based verification for an object oriented concurrency model"
    - "coffman deadlocks in scoop"

Connected through hyperedge HE-4 (induced by source paper "autoproof auto active functional verification of object oriented programs"):
  with members:
    - "the autoproof verifier usability by non experts and on standard code"
    - "flexible invariants through semantic collaboration"
    - "rotation of sequences algorithms and proofs"
    - "specifying reusable components"

Connected through hyperedge HE-5 (induced by source paper "towards practical graph based verification for an object oriented concurrency model"):
  with members:
    - "verifying monadic second order properties of graph programs"
    - "coffman deadlocks in scoop"
    - "queue dispatch asynchronous systems"

Connected through hyperedge HE-6 (induced by source paper "modelling and verifying an object oriented concurrency model in groove"):
  with members:
    - "towards practical graph based verification for an object oriented concurrency model"
    - "coffman deadlocks in scoop"

Connected through hyperedge HE-7 (induced by source paper "contract based general purpose gpu programming"):
  with members:
    - "a comparative study of programming languages in rosetta code"
    - "pycuda and pyopencl a scripting based approach to gpu run time code generation"

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.DC(Distributed, Parallel, and Cluster Computing)