Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Quantum Private Information Retrieval has linear communication
  complexity
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex