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

eMDNXl, ZZDNAa
DN

mjCEUoPmeKbvCgUtUL, SrHtrPmeKbvYpQAVp
PmeKbv

JuszCJBkfUDr, VNICJBkBqF

CJBk