Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Robust Humanoid Locomotion Using Trajectory Optimization and
  Sample-Efficient Learning
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int