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

Q: euQWhCovKplukMYznXcD, XAfMhKdzhCovKplukMcMlSuBw

A: hCovKplukM
****
Q: cjDuPZOHjystHnF, okWVdUDuPZOHjSCaEecP

A: DuPZOHj
****
Q: IFHqitRXfNbSKsej, qVJWXuitRXfNbSKXmT

A:
itRXfNbSK
****