instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
UovaYpHjYSQzrfsxRfvIZE, pUOFxIKOGQzrfsxRfvIjrza
answer:
QzrfsxRfvI


question:
eeoJEtGHPDvHck, ezPGHPDvHSf
answer:
GHPDvH


question:
qBwPFTHBfYipZvSF, fBFQTHBfYipHzqnJAI
answer:

THBfYip