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

Q: qMnjlfIsQRtUlPggCpHqu, gfVndMwYDIsQRtUlPgqBJKCX

A: IsQRtUlPg
****
Q: spUbdWDLWCeqr, vIuHkWDLWCQEPaz

A: WDLWC
****
Q: uCrwIVczObxmJbkIRcvGT, bCpEObxmJbkImOnLEFu

A:
ObxmJbkI
****