instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
jJjsASFfCqVV, AkjsASFfBFwPy
answer:
jsASFf


question:
wDSKHtWbCDqTeoBeiYHdcZD, MydQCwqTeoBeiYHdYMp
answer:
qTeoBeiYHd


question:
AIthnouSQnoItD, HHWethnouSjGrJ
answer:

thnouS