instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
SJIkEibGrqcrOBgGjYjJc, EervOGrqcrOBgGJZyx
answer:
GrqcrOBgG


question:
ilgSzrcUKLTNLJbMKMKSt, hFXIuUKLTNLJbMKWxSCkDjY
answer:
UKLTNLJbMK


question:
NWdLJjeCMwUYWCxJVK, lPKYjeCMwUYWFbinoVi
answer:

jeCMwUYW