Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Directed transport in a ratchet with internal and chemical freedoms
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs