instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
XbjDHRCWxdPbhibUKn, SrpuPDHRCWxdPbKPWEXNWbZ
answer:
DHRCWxdPb


question:
zeuyZKwvIOfx, BlmZKwvspUt
answer:
ZKwv


question:
QIxnzXlJHRCjQiczbUGR, FErSxryTHRCjQiczbUQbNM
answer:

HRCjQiczbU