Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A Mathematical Approach to Improve Energy-Water Nexus Reliability Using
  a Novel Multi-Stage Adjustable Fuzzy Robust Approach
18
The categories of this paper are: econ
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph