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

oZNKLmfxecDfkXEGFkRBYk, tReqkiExecDfkXEGtNZpJVRxC
xecDfkXEG

jsXHot, gtXHmB
XH

ECiWeUDoGF, BiLWiWeUsKV

iWeU