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]: oXZmCSdFrMumlZcP, eFpOZmCSdFrIuHeS
[A]: ZmCSdFr


[Q]: wJbfZaIDseOe, hjaIDseSdpN
[A]:
aIDse