TASK DEFINITION: In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
PROBLEM: koIZvrJmfKCO, TBvrtjcWIZvrJmfKRZDOE

SOLUTION: IZvrJmfK

PROBLEM: ZRjPgqbLL, uIsmPgqbBB

SOLUTION: Pgqb

PROBLEM: KvurPMpgvR, YOrPMpgukCUK

SOLUTION:
rPMpg