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

Q: esIMEOgV, tNIMEybb

A: IME
****
Q: iwSQnplQZFbXQ, lHWnplQZFzswgU

A: nplQZF
****
Q: rjOAfE, bFOAjY

A:
OA
****