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

OBzHWjmkcgVGPyv, gCHWjmkcgVMq
HWjmkcgV

HhBhJMpxpty, MxTJMpxnQEf
JMpx

uMUkhBwSdsCqoyMlsHPXi, jMEjNUkhBwSdsCqSNizWNT

UkhBwSdsCq