instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
yITbYie, TlqTbYomH
answer:
TbY


question:
NUuLSmDjCKcJPc, lGGSLIDjCKcJBo
answer:
DjCKcJ


question:
NRkUlPjgKzYWzICkK, oyhojgKzYWxrpbP
answer:

jgKzYW