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

RwduMBkDazrwZP, UPzcwtWMBkDazrAw
MBkDazr

ohueEOjHvAuoFVmMFft, ovdJPqOjHvAuoFVGbvxzlnE
OjHvAuoFV

ktkyBuJFWtVmQgdRrapPGUCw, igLoDNiFWtVmQgdROKR

FWtVmQgdR