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

SOLUTION: Kscqiz

PROBLEM: IJQqdzqdaGEIcdyh, izlVdzqdaGGiPYz

SOLUTION: dzqdaG

PROBLEM: MkntiwsJlLL, YBPyntiwsJSfMd

SOLUTION:
ntiwsJ