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

RGImMTISYdkjzMO, pmyfpImMTISYdatLBBFr
ImMTISYd

egYXVtCPvWxP, VMOolyVtCPvWjIx
VtCPvW

zpxsfHSrosXBLTwJKwKulD, IIfrosXBLTwirwCoLV

rosXBLTw