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

[Q]: nYoRQU, gQoRZQ
[A]: oR


[Q]: eFUexDIFlaPDUwrOb, mTvkKGUxDIFlaPDUwxGVpnIwbi
[A]: xDIFlaPDUw


[Q]: gAfWdzvGXiIjmpgYe, XlfPIldzvGXiIjmleAKn
[A]:
dzvGXiIjm