instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
kWnjCoVmCSVuW, RILPKCoVmCSVbaOza
answer:
CoVmCSV


question:
iJbjApY, ggwbjAws
answer:
bjA


question:
HwBeXPEOLPNUZdmVsVgN, bufLGrBeXPEOLPNuHkzVA
answer:

BeXPEOLPN