In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

[Q]: QRPOwtZATjDoJDdRNNSOH, wiafFMwpAjDoJDdRNNuCDZ
[A]: jDoJDdRNN


[Q]: tftBHoDOYxCoTHVf, qhHoDOYxfUU
[A]: HoDOYx


[Q]: JAsqdlpv, yuGqdliY
[A]:
qdl