Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Uma prova elementar da f\'ormula de Euler usando o m\'etodo de Cauchy   The use of Cauchy's method in proving the well-known Euler formula is an
object of many controversies. The purpose of this paper is to prove that the
Cauchy's method applies for convex polyhedra and not only for them, but also
for surfaces such as the torus, the projective plane, the Klein bottle and the
pinched torus.

35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics