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

Q: qMnjlfIsQRtUlPggCpHqu, gfVndMwYDIsQRtUlPgqBJKCX

A: IsQRtUlPg
****
Q: koddLvYmRXDUuUnW, GnqDYGmmRXDUuUquAnf

A: mRXDUuU
****
Q: fdinRdwwlntwqzYGhV, ZefonRdwwlntoWQbh

A:
nRdwwlnt
****