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

SOLUTION: FobZE

PROBLEM: njzfcapS, JDzfcYQh

SOLUTION: zfc

PROBLEM: EKXjSHQvIBJGHcUiFlq, NcRXjSHQvIBJFCMMaNBYR

SOLUTION:
XjSHQvIBJ