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

mjCEUoPmeKbvCgUtUL, SrHtrPmeKbvYpQAVp
PmeKbv

aBlALASwuwTZmy, MdwASwuwIW
ASwuw

kiSTsH, VPSTjk

ST