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

[Q]: lrBJDRkT, jmBJDrI
[A]: BJD


[Q]: sCMyALRSDknURKqZDlqFf, oEIfHyALRSDknUrnMebev
[A]: yALRSDknU


[Q]: UDOTfqESle, gnzOTfqEoTx
[A]:
OTfqE