instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
CUlMsvov, iflMsSRp
answer:
lMs


question:
IzwlZDJSEFPxfIud, xwWSYwlZDJSEFPbvSXTlS
answer:
wlZDJSEFP


question:
sAsAyIIPReWRm, XrkUIIPReWZGsfx
answer:

IIPReW