Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Necessary and sufficient conditions for the inverse problem of one class
  ordinary differential operators with complex periodic coefficients
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con