In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
--------
Question: iMwanJBuMdiZDL, kIafHeBuMdiZmKNA

Answer: BuMdiZ


Question: YXsgPE, ENsgSO

Answer: sg


Question: nvGcdypYW, qucdypSXK

Answer:
cdyp