instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
jLbHvZmecfxMcGLXGVsO, erFBGmecfxMcJtDyKGZ
answer:
mecfxMc


question:
UldKHMpUYADGfEUGcSon, nPHMpUYADGfEKqHCLPmL
answer:
HMpUYADGfE


question:
eGhwbCecZLZAZEmEzvOP, mMRdSRwbCecZLZALSVUEq
answer:

wbCecZLZA