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

Ex Input:
TnHJcxtwcZ, XFdHJcxNKw

Ex Output:
HJcx


Ex Input:
qMnjlfIsQRtUlPggCpHqu, gfVndMwYDIsQRtUlPgqBJKCX

Ex Output:
IsQRtUlPg


Ex Input:
GGlcJCpyYW, kRklcJCpyBnadu

Ex Output:

lcJCpy