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

Ex Input:
rszjOPpbXm, pnBujOPpWHz

Ex Output:
jOPp


Ex Input:
lQwpMQRxuVbJDv, UkzwpMQRxuDVT

Ex Output:
wpMQRxu


Ex Input:
CXNJqtdoXALzqga, wgtdoXAprZpT

Ex Output:

tdoXA