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

[Q]: XbjDHRCWxdPbhibUKn, SrpuPDHRCWxdPbKPWEXNWbZ
[A]: DHRCWxdPb


[Q]: mXHhaCEIwqwEZcz, JZPXbYHhaCEIwZmna
[A]: HhaCEIw


[Q]: yVxFpNBtXv, HEnxFpNBPcMk
[A]:
xFpNB