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: "dna codes that avoid secondary structures"
  Abstract: In this paper, we consider the problem of designing codewords for DNA storage systems and DNA computers that are unlikely to fold back onto themselves to form undesirable secondary structures. Secondary structure formation causes a DNA codeword to become less active chemically, thus rendering it useless for the purpose of DNA computing. It also defeats the read-back mechanism in a DNA storage system, so that information stored in such a folded DNA codeword cannot be retrieved. Based on some simple properties of a dynamic-programming algorithm, known as Nussinov's method, which is an effective predictor of secondary structure given the sequence of bases in a DNA codeword, we identify some design criteria that reduce the possibility of secondary structure formation in a codeword. These design criteria can be formulated in terms of the requirement that the Watson-Crick distance between a DNA codeword and a number of its shifts be larger than a given threshold. This paper addresses both the issue of enumerating DNA sequences with such properties and the problem of practical DNA code construction

Connected through hyperedge HE-1 (induced by source paper "on conflict free dna codes"):
  with members:
    - "asymptotically optimal codes correcting fixed length duplication errors in dna storage systems"
    - "properties and constructions of constrained codes for dna based data storage"
    - "the art of dna strings sixteen years of dna coding theory"
    - "a rewritable random access dna based storage system"
    - "codes for dna sequence profiles"
    - "natural data storage a review on sending information from now to then via nature"

Connected through hyperedge HE-2 (induced by source paper "modular non repeating codes for dna storage"):
  with members:
    - "codes in the damerau distance for dna storage"
    - "duplication correcting codes for data storage in the dna of living organisms"
    - "asymmetric lee distance codes for dna based storage"
    - "a rewritable random access dna based storage system"
    - "on optimal family of codes for dna storage"
    - "codes for dna storage channels"
    - "loopy belief propagation for approximate inference an empirical study"
    - "a generic top down dynamic programming approach to prefix free coding"

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)