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

ktABEFESAVHZkkY, uMjxiESAVHZkZgWUte
ESAVHZk

UysTOtIRtRorNAFKKYD, icDOtIRtRoropYVaKzJ
OtIRtRor

zVmMGcQtofbqjDRmCk, ksQtofbqjDRNBMrexPx

QtofbqjDR