instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
OUNqomxFcLXhWdfB, gdqomxFcLHQPCu
answer:
qomxFcL


question:
OyXwTWbLByC, yODnTWbLWYzc
answer:
TWbL


question:
tQwDaSFaUirPF, clDaSFaUjN
answer:

DaSFaU