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

Input: Consider Input: rvLoiycpZw, idcvoiycpcLyD

Output: oiycp


Input: Consider Input: cfvqbAUpWEmhCSFaUvGrYVNGeUiRP, hAxWMEmhCSFaUvGLBLmdTxhy

Output: EmhCSFaUvG


Input: Consider Input: IDYgtO, ouYggp


Output: Yg