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

Ex Input:
ZGkBNEDRAwURXnxBIOJkzTvg, HMAwURXnxBMfGbPOBf

Ex Output:
AwURXnxB


Ex Input:
jyJrDIhxJtWbnooEXZ, uyXifNCIhxJtWbnVCUrt

Ex Output:
IhxJtWbn


Ex Input:
ZwnWAwLCNWtc, KBbTpnWAwLonRO

Ex Output:

nWAwL