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

[EX Q]: gwVLygvd, VOQLyglfo
[EX A]: Lyg

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

[EX Q]: JYpKRX, ajpKhF
[EX A]:
pK