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: "zero forcing number constrained matchings and strong structural controllability"
  Abstract: The zero forcing number is a graph invariant introduced to study the minimum rank of the graph. In 2008, Aazami proved the NP-hardness of computing the zero forcing number of a simple undirected graph. We complete this NP-hardness result by showing that the non-equivalent problem of computing the zero forcing number of a directed graph allowing loops is also NP-hard. The rest of the paper is devoted to the strong controllability of a networked system. This kind of controllability takes into account only the structure of the interconnection graph, but not the interconnection strengths along the edges. We provide a necessary and sufficient condition in terms of zero forcing sets for the strong controllability of a system whose underlying graph is a directed graph allowing loops. Moreover, we explain how our result differs from a recent related result discovered by Monshizadeh et al. Finally, we show how to solve the problem of finding efficiently a minimum-size input set for the strong controllability of a self-damped system with a tree-structure.

Connected through hyperedge HE-1 (induced by source paper "optimal regulation of flow networks with transient constraints"):
  with members:
    - "on resilient control of dynamical flow networks"
    - "modeling and control of hvdc transmission systems from theory to practice and back"
    - "a compartmental model for traffic networks and its dynamical behavior"
    - "zero forcing sets and controllability of dynamical systems defined on graphs"
    - "an internal model approach to optimal frequency regulation in power grids with time varying voltages"
    - "dynamic coupling design for nonlinear output agreement and time varying flow control"

Connected through hyperedge HE-2 (induced by source paper "computational approaches for zero forcing and related problems"):
  with members:
    - "graphs with extremal connected forcing numbers"
    - "complexity and computation of connected zero forcing"
    - "characterizations of the connected forcing number of a graph"
    - "logic circuits from zero forcing"
    - "domination in graphs with bounded propagation algorithms formulations and hardness results"

Connected through hyperedge HE-3 (induced by source paper "graphs with extremal connected forcing numbers"):
  with members:
    - "complexity and computation of connected zero forcing"
    - "characterizations of the connected forcing number of a graph"
    - "logic circuits from zero forcing"

Connected through hyperedge HE-4 (induced by source paper "complexity and computation of connected zero forcing"):
  with members:
    - "characterizations of the connected forcing number of a graph"
    - "logic circuits from zero forcing"
    - "spanning trees and the complexity of flood filling games"

Connected through hyperedge HE-5 (induced by source paper "characterizations of the connected forcing number of a graph"):
  with members:
    - "logic circuits from zero forcing"
    - "a graph reduction step preserving element connectivity and applications"

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)