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

SOLUTION: PmeKbv

PROBLEM: GrvtMjEvRlmN, ifGOWMjEvRPSOZK

SOLUTION: MjEvR

PROBLEM: dGGXOhIbvxrmZEL, JnlLGXOhIbvxjBuhH

SOLUTION:
GXOhIbvx