Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A solution of $3x+1$ problem   We present a solution of $3x+1$ problem. For a history of this problem we
refer the reader to Lagarias, Jeffrey C.

19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs