instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
iupYjFXrrMqWzJSLUSwmEukHc, hqajjWrrMqWzJSLnF
answer:
rrMqWzJSL


question:
xeKSiBafhOWBbYwlGaQ, GUfIsKgafhOWBbYiFWnptAt
answer:
afhOWBbY


question:
hXhcsK, vFhcUL
answer:

hc