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

Ex Input:
gHFwDorPbNPORVgdLW, AfqDQvCGFwDorPbNPVPVmbQ

Ex Output:
FwDorPbNP


Ex Input:
DZfOjrQffR, CXOjrQQc

Ex Output:
OjrQ


Ex Input:
tVQraoypp, YRQraoin

Ex Output:

Qrao