instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
jyJrDIhxJtWbnooEXZ, uyXifNCIhxJtWbnVCUrt
answer:
IhxJtWbn


question:
sHndIbPaygfNvnquxIHeteW, huLmJWXZIgfNvnquxIViQDhbuoL
answer:
gfNvnquxI


question:
MYGtMfFrSmYKscstxAxw, BdUVuZQarSmYKscstakPB
answer:

rSmYKscst