instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
MSxTzCpiJAplpzSvLlNJS, oScCpiJAplpNVrqkn
answer:
CpiJAplp


question:
WTnsmP, INnsIM
answer:
ns


question:
YONkfBAMlzExCQfbpgCtm, TdMlzExCQfbfsvOAnXsz
answer:

MlzExCQfb