instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
OBzHWjmkcgVGPyv, gCHWjmkcgVMq
answer:
HWjmkcgV


question:
VpJvIZdkzKovjc, BZEizZdkzKYZ
answer:
ZdkzK


question:
IQGvZorspoCObtdYRgoqml, CJIcspoCObtdYDuu
answer:

spoCObtdY