In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

zmbmQuyNGOe, mUMEmQuyiuS
mQuy

pJqqIW, Ivqqxw
qq

wShkkdBxJkjWqu, haIoFRqhkkdBxJPXGqnd

hkkdBxJ