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

SIIPePlrkftKkzfgdjg, JqNnXHrkftKkzOMUwmc
rkftKkz

QKlzsmHyBcC, snPtzsmHdMIv
zsmH

yaTLrEIdecvXsxfb, ddLrEIdecUWFid

LrEIdec