instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
iaXeqfIrYKxPJRXxfSm, rIYKxPJRXxfsjVsqe
answer:
YKxPJRXxf


question:
UQDJDbzqDxsMzUL, BxClJDbzqDxLxlngc
answer:
JDbzqDx


question:
fSYcNfygdsgXwNYQEEfQ, OhWXYgdsgXwNYQmhnJqT
answer:

gdsgXwNYQ