instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
mjCEUoPmeKbvCgUtUL, SrHtrPmeKbvYpQAVp
answer:
PmeKbv


question:
GnElFKBIoYmAdvz, GrElFKBIoMo
answer:
ElFKBIo


question:
mkCKDiRtoRYEQGnP, ZeosHiRtoRYxPjK
answer:

iRtoRY