Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Quantum-well and modified image-potential states in thin Pb(111) films:
  an estimate for the local work function
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph