instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
mRVieYomZqJXaTDsShCyfPW, ifOAlnptmZqJXaTDsVMqY
answer:
mZqJXaTDs


question:
PIcbiJj, hedcbiZHF
answer:
cbi


question:
KULgSG, pGLgLf
answer:

Lg