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

SOLUTION: MjEvR

PROBLEM: rRmkmETbjzCzZZxihrVdefxfcenJ, ogQtzAgWjKCzZZxihrVdRswMCmngp

SOLUTION: CzZZxihrVd

PROBLEM: lVQOcFm, aueQOcvDO

SOLUTION:
QOc