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

SOLUTION: we

PROBLEM: GnElFKBIoYmAdvz, GrElFKBIoMo

SOLUTION: ElFKBIo

PROBLEM: PQSFjlnU, kTSFjMUh

SOLUTION:
SFj