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

sRpnJlgECTHh, JXfmNJlgECKyry
JlgEC

AedXEOrEgvnzF, TVTEOrEgvxKuJgv
EOrEgv

qPYQAdVkSnpWaD, zhAdVkSnFYX

AdVkSn