instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
umXfmRnUgALpFAqBaKfNfo, aOAXWnUgALpFAqBmNpTCdj
answer:
nUgALpFAqB


question:
sbQJFbUtmnKaEJePFPeRM, QzfvkdZbUtmnKaEJNrWD
answer:
bUtmnKaEJ


question:
OYzEjPjENZoEKRDVduwAln, BpNZoEKRDVdcqpWiXR
answer:

NZoEKRDVd