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

Example Input: BdqUloJanutXoOyfLsuA, NRDloJanutXoOQY
Example Output: loJanutXoO

Example Input: VRamNL, mUamIB
Example Output: am

Example Input: EIECDcMeUrZkohCzqKfHl, GXqoyMeUrZkohCxY
Example Output:
MeUrZkohC