instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
SyweIt, ILweip
answer:
we


question:
kOrQWjLKnwN, xFsWjLKgr
answer:
WjLK


question:
lhVlRByJhMeVnWFsrtcWDRX, FScHyNTrlRByJhMeVnsIFypASMx
answer:

lRByJhMeVn