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

[EX Q]: wcJmSloqlddFOfv, szhUIAqzSloqlddFDJz
[EX A]: SloqlddF

[EX Q]: BfCCzPNLBbwCoxMVAG, vhwNLBbwCbH
[EX A]: NLBbwC

[EX Q]: YRNpKFPGzUsgCOBJgbVG, TdEpMngFPGzUsgCOZykYRrLp
[EX A]:
FPGzUsgCO