Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Improving the Flexibility and Robustness of Model-Based Derivative-Free
  Optimization Solvers
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom