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

Input: Consider Input: ptVlCwpfOZIi, QEdyVlCwpfOwp

Output: VlCwpfO


Input: Consider Input: QKlzsmHyBcC, snPtzsmHdMIv

Output: zsmH


Input: Consider Input: UFiDDucWtbmGQgC, xsVUtQDDucWtPmOPt


Output: DDucWt