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

vFuggVITQuctFG, hdCIWWuuggVITQwr
uggVITQ

SODsrWUjUBSgA, WIWUjUBCUUs
WUjUB

QJqpGTCUzsAFpB, YIgGqpGTCUyyIbz

qpGTCU