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

SOLUTION: nz

PROBLEM: rEHxRBOktYreNkK, NCOktYreFFCFwi

SOLUTION: OktYre

PROBLEM: IDWuCt, NpWuZE

SOLUTION:
Wu