Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Multi-mJ, kHz, 2.1-$\mu$m OPCPA for high-flux soft X-ray high-harmonic
  radiation
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con