instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
YCAyruPTTHWhCYaiXfIl, OETdzqAyruPTTHWgS
answer:
AyruPTTHW


question:
jAinxmaQUrmu, jqeEnxmaQUrWlrEqW
answer:
nxmaQUr


question:
tpGCqaoaR, UnCqagL
answer:

Cqa