In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
--------
Question: aiqZheFuLtXAGRCGNBTAX, ssnVdztXAGRCGNBTIqmSJLZcy

Answer: tXAGRCGNBT


Question: ftvxfhsnJEygzV, JYxSfhsnJnIqkW

Answer: fhsnJ


Question: FQAznAuFjoBKRKB, hPmtFFPnuAznAuFjoBKTgkeJyjcd

Answer:
AznAuFjoBK