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

Q: cZSEmdgP, YsSEmEIM

A: SEm
****
Q: zBNTHKtofMdHfBgJhOfojzM, VIkVdFapofMdHfBgjPCUo

A: ofMdHfBg
****
Q: JWBpuXr, HsmBpuej

A:
Bpu
****