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: "minimum cost and list homomorphisms to semicomplete digraphs"
  Abstract: The following optimization problem was introduced in \cite{gutinDAM}, where it was motivated by a real-world problem in defence logistics. Suppose we are given a pair of digraphs $D,H$ and a positive cost $c_i(u)$ for each $u\in V(D)$ and $i\in V(H)$. The cost of a homomorphism $f$ of $D$ to $H$ is $\sum_{u\in V(D)}c_{f(u)}(u)$. For a fixed digraph $H$, the minimum cost homomorphism problem for $H$, MinHOMP($H$), is stated as follows: For an input digraph $D$ and costs $c_i(u)$ for each $u\in V(D)$ and $i\in V(H)$, verify whether there is a homomorphism of $D$ to $H$ and, if it exists, find such a homomorphism of minimum cost. #R##N#We obtain dichotomy classifications of the computational complexity of the list homomorphism problem and MinHOMP($H$), when $H$ is a semicomplete digraph (a digraph in which every two vertices have at least one arc between them). Our dichotomy for the list homomorphism problem coincides with the one obtained by Bang-Jensen, Hell and MacGillivray in 1988 for the homomorphism problem when $H$ is a semicomplete digraph: both problems are polynomial solvable if $H$ has at most one cycle; otherwise, both problems are NP-complete. The dichotomy for \MiP is different: the problem is polynomial time solvable if $H$ is acyclic or $H$ is a cycle of length 2 or 3; otherwise, the problem is NP-hard.

Connected through hyperedge HE-1 (induced by source paper "space complexity of list h coloring revisited the case of oriented trees"):
  with members:
    - "space complexity of list h colouring a dichotomy"
    - "list h coloring a graph by removing few vertices"
    - "the dichotomy of list homomorphisms for digraphs"
    - "the complexity of the list homomorphism problem for graphs"

Connected through hyperedge HE-2 (induced by source paper "list h coloring a graph by removing few vertices"):
  with members:
    - "clustering with local restrictions"
    - "space complexity of list h colouring a dichotomy"
    - "faster parameterized algorithms using linear programming"
    - "fixed parameter tractability of multicut in directed acyclic graphs"
    - "directed subset feedback vertex set is fixed parameter tractable"
    - "finding small separators in linear time via treewidth reduction"
    - "fixed parameter tractability of directed multiway cut parameterized by the size of the cutset"
    - "on multiway cut parameterized above lower bounds"

Connected through hyperedge HE-3 (induced by source paper "extensions of the minimum cost homomorphism problem"):
  with members:
    - "duality for min max orderings and dichotomy for min cost homomorphisms"
    - "minimum cost homomorphisms to reflexive digraphs"

Connected through hyperedge HE-4 (induced by source paper "duality for min max orderings and dichotomy for min cost homomorphisms"):
  with members:
    - "a maximal tractable class of soft constraints"
    - "minimum cost homomorphisms to reflexive digraphs"

Connected through hyperedge HE-5 (induced by source paper "minimum cost homomorphisms to locally semicomplete and quasi transitive digraphs"):
  with members:
    - "a maximal tractable class of soft constraints"
    - "minimum cost homomorphisms to reflexive digraphs"
    - "minimum cost homomorphisms to semicomplete multipartite digraphs"

Connected through hyperedge HE-6 (induced by source paper "minimum cost homomorphisms to reflexive digraphs"):
  with members:
    - "a maximal tractable class of soft constraints"
    - "on the complexity of the minimum cost homomorphism problem for reflexive multipartite tournaments"
    - "minimum cost homomorphisms to semicomplete multipartite digraphs"

Connected through hyperedge HE-7 (induced by source paper "on the complexity of the minimum cost homomorphism problem for reflexive multipartite tournaments"):
  with members:
    - "minimum cost homomorphisms to proper interval graphs and bigraphs"
    - "minimum cost homomorphisms to semicomplete multipartite digraphs"

Connected through hyperedge HE-8 (induced by source paper "complexity of the minimum cost homomorphism problem for semicomplete digraphs with possible loops"):
  with members:
    - "minimum cost homomorphisms to semicomplete multipartite digraphs"

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)