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

Q: IKrQfT, crrQRg

A: rQ
****
Q: nuwMzarLqoPvabJla, JKcrLqoPvabJNDCILGQ

A: rLqoPvabJ
****
Q: YZpcACFxXhswYksITnG, ctwBFzNxXhswYksIlPx

A:
xXhswYksI
****