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

Q: spGRUmIYuGl, qkqRUmItqU

A: RUmI
****
Q: vJtmxQmHEq, yobgAtmxQmMeoLz

A: tmxQm
****
Q: dSfSeKqevswhlNNb, KLcmvFlqevswhlTRJ

A:
qevswhl
****
