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

Example Input: wcJmSloqlddFOfv, szhUIAqzSloqlddFDJz
Example Output: SloqlddF

Example Input: EJZYVxgFxPoOSDlLfK, uTLTIETHZYVxgFxPoPwr
Example Output: ZYVxgFxPo

Example Input: IBkvOWTqeJM, SKZvOWTYfDs
Example Output:
vOWT