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

qczzCr, zDzzUI
zz

PivhPfah, XSghPfOi
hPf

ZClupMFQVvWCUuiTpxWHiBuL, fxsQsZVkpVvWCUuiTpxcDWfpsLY

VvWCUuiTpx