instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
GFhJafTV, waHhJaji
answer:
hJa


question:
euQWhCovKplukMYznXcD, XAfMhKdzhCovKplukMcMlSuBw
answer:
hCovKplukM


question:
wdiMPlykLCwy, IulykLCPBxOq
answer:

lykLC