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

Q: CxosNa, ikosdx

A: os
****
Q: ezVsFayUPcrte, lfsFayUMPTqx

A: sFayU
****
Q: PuyomnTXa, dGomnZE

A:
omn
****