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

[EX Q]: nYoRQU, gQoRZQ
[EX A]: oR

[EX Q]: esIMEOgV, tNIMEybb
[EX A]: IME

[EX Q]: VoRzKdBELaJjcCeTH, dDzKdBELaRPORT
[EX A]:
zKdBELa

