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

RinootTGLjbRGYznmBdH, oRMtTGLjbRGYzwEVHsjW
tTGLjbRGYz

ljwjMioOwfOltGBaE, TneNGsoOwfOlxnWWW
oOwfOl

xlRATLKitmTtvffCulmXteOmFpkA, WFHmTtvffCulmhIe

mTtvffCulm