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

Ex Input:
cfvqbAUpWEmhCSFaUvGrYVNGeUiRP, hAxWMEmhCSFaUvGLBLmdTxhy

Ex Output:
EmhCSFaUvG


Ex Input:
nxoXDohHr, WcbkXDohFbJ

Ex Output:
XDoh


Ex Input:
NlqjrAQM, htqjrjF

Ex Output:

qjr