instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
ilgSzrcUKLTNLJbMKMKSt, hFXIuUKLTNLJbMKWxSCkDjY
answer:
UKLTNLJbMK


question:
OgWFOfjNYmXVjBBvOdunIc, eGljKGnzFKFOfjNYmXVjdlqsT
answer:
FOfjNYmXVj


question:
MlywtOS, btaywtYgm
answer:

ywt