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: "exponential lower bounds for policy iteration"
  Abstract: We study policy iteration for infinite-horizon Markov decision processes. It has recently been shown policy iteration style algorithms have exponential lower bounds in a two player game setting. We extend these lower bounds to Markov decision processes with the total reward and average-reward optimality criteria.

Connected through hyperedge HE-1 (induced by source paper "a universal attractor decomposition algorithm for parity games"):
  with members:
    - "practical synthesis of reactive systems from ltl specifications via parity games"
    - "improving the complexity of parys recursive algorithm"
    - "alternating weak automata from universal trees"
    - "computing nested fixpoints in quasipolynomial time"
    - "parity games zielonka s algorithm in quasi polynomial time"
    - "fixpoint games on continuous lattices"
    - "quasipolynomial set based symbolic algorithms for parity games"
    - "oink an implementation and evaluation of modern parity game solvers"

Connected through hyperedge HE-2 (induced by source paper "the strahler number of a parity game"):
  with members:
    - "a universal attractor decomposition algorithm for parity games"
    - "parity games another view on lehtinen s algorithm"
    - "alternating weak automata from universal trees"
    - "computing nested fixpoints in quasipolynomial time"
    - "parity games zielonka s algorithm in quasi polynomial time"
    - "universal trees grow inside separating automata quasi polynomial lower bounds for parity games"
    - "succinct progress measures for solving parity games"

Connected through hyperedge HE-3 (induced by source paper "parity games zielonka s algorithm in quasi polynomial time"):
  with members:
    - "oink an implementation and evaluation of modern parity game solvers"
    - "universal trees grow inside separating automata quasi polynomial lower bounds for parity games"
    - "robust exponential worst cases for divide et impera algorithms for parity games"
    - "efficient parallel strategy improvement for parity games"
    - "a short proof of correctness of the quasi polynomial time algorithm for parity games"
    - "an ordered approach to solving parity games in quasi polynomial time and quasi linear space"

Connected through hyperedge HE-4 (induced by source paper "parity games another view on lehtinen s algorithm"):
  with members:
    - "universal trees grow inside separating automata quasi polynomial lower bounds for parity games"
    - "a short proof of correctness of the quasi polynomial time algorithm for parity games"
    - "an ordered approach to solving parity games in quasi polynomial time and quasi linear space"
    - "playing pushdown parity games in a hurry"

Connected through hyperedge HE-5 (induced by source paper "toward solving 2 tbsg efficiently"):
  with members:
    - "the simplex method is strongly polynomial for deterministic markov decision processes"
    - "strategy iteration is strongly polynomial for 2 player turn based stochastic games with a constant discount factor"

Connected through hyperedge HE-6 (induced by source paper "universal trees grow inside separating automata quasi polynomial lower bounds for parity games"):
  with members:
    - "an optimal value iteration algorithm for parity games"
    - "an ordered approach to solving parity games in quasi polynomial time and quasi linear space"
    - "succinct progress measures for solving parity games"
    - "improved algorithms for parity and streett objectives"

Connected through hyperedge HE-7 (induced by source paper "efficient strategy iteration for mean payoff in markov decision processes"):
  with members:
    - "value iteration for long run average reward in markov decision processes"
    - "efficient parallel strategy improvement for parity games"
    - "synthesising strategy improvement and recursive algorithms for solving 2 5 player parity games"
    - "multigain a controller synthesis tool for mdps with multiple mean payoff objectives"
    - "verification of markov decision processes using learning algorithms"
    - "parametric strategy iteration"
    - "assume guarantee abstraction refinement for probabilistic systems"
    - "using strategy improvement to stay alive"

Connected through hyperedge HE-8 (induced by source paper "the stochastic shortest path problem a polyhedral combinatorics perspective"):
  with members:
    - "the value iteration algorithm is not strongly polynomial for discounted dynamic programming"
    - "strategy iteration is strongly polynomial for 2 player turn based stochastic games with a constant discount factor"

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.DS(Data Structures and Algorithms)