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

[Q]: DGvUCrUVlUnQBShkWnfnceGasvI, NfzGUnQBShkWnpLMnY
[A]: UnQBShkWn


[Q]: xeKSiBafhOWBbYwlGaQ, GUfIsKgafhOWBbYiFWnptAt
[A]: afhOWBbY


[Q]: sQcKJYhLmnBLmgAu, KVhLmnBLQI
[A]:
hLmnBL