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

Q: UldKHMpUYADGfEUGcSon, nPHMpUYADGfEKqHCLPmL

A: HMpUYADGfE
****
Q: GnElFKBIoYmAdvz, GrElFKBIoMo

A: ElFKBIo
****
Q: XwBMFIV, SNLBMFZQ

A:
BMF
****