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

uGDJixAmSiVaFRmfKRM, NsTGxsJixAmSiVageSw
JixAmSiVa

mRVieYomZqJXaTDsShCyfPW, ifOAlnptmZqJXaTDsVMqY
mZqJXaTDs

QLZJPqgym, beJPqDA

JPq