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

Q: sbQJFbUtmnKaEJePFPeRM, QzfvkdZbUtmnKaEJNrWD

A: bUtmnKaEJ
****
Q: UiaECWZf, gRyaECWLGRl

A: aECW
****
Q: DqTstXaRoSflSYLnW, apPXaRoSflicjXV

A:
XaRoSfl
****