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

sRpnJlgECTHh, JXfmNJlgECKyry
JlgEC

pJqqIW, Ivqqxw
qq

zMQecwcUAFHvoCIWO, RmJTyTIJcwcUAFHvoeDRHiCpe

cwcUAFHvo