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

Q: KvPFobZEGs, eKFobZEtnm

A: FobZE
****
Q: GHdeqnuYnQ, zzQeqnutAZ

A: eqnu
****
Q: ZTnJCVbqUkKOXAPs, iMCAhAnJCVbqUkKOUhstZ

A:
nJCVbqUkKO
****