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

[EX Q]: uZSRkFDHsGXNMaggxUn, lTrQKKpsGXNMaggEdSrEX
[EX A]: sGXNMagg

[EX Q]: UmYbssMbmsXkKQuzNasLOib, EMqlbmsXkKQuzNcyHrpZXOQW
[EX A]: bmsXkKQuzN

[EX Q]: ZxouxhkRoiziZsNk, NlRdowFefKuxhkRoiziZAlTM
[EX A]:
uxhkRoiziZ