Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the anomalous {changes of seismicity and} geomagnetic field prior to
  the 2011 $M_w$ 9.0 Tohoku earthquake
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph