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

uDaqoOpUtLDdTGTO, ncIgBjDPqoOpUtLDdTNtiEyarDO
qoOpUtLDdT

VutZiVkDQcVpQO, BDQVDyBdiVkDQcVpuvNN
iVkDQcVp

bJfsvNsQkzIZSrdT, HFbYsQkzIZcWNQZI

sQkzIZ