instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
DhhYhrqVMXSoyvXQwqPKzWARAP, CaMXSoyvXQwqcDDtMsVqD
answer:
MXSoyvXQwq


question:
kvutZfcPKzHE, kTKutZfcPTGmU
answer:
utZfcP


question:
lSOLCNxGHqnGtvFtwGX, oTWCLxGHqnGtvgG
answer:

xGHqnGtv