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

Q: VGRjWGHRcBdFmkVg, eSwqALQXWGHRcBdFsDXCM

A: WGHRcBdF
****
Q: aeQjEeiWGONmzGimhGiw, RIEeiWGONmOZuVYr

A: EeiWGONm
****
Q: HXHAUXcFGkKFzx, MhUUXcFGkKFJT

A:
UXcFGkKF
****