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

SOLUTION: oiycp

PROBLEM: GHdeqnuYnQ, zzQeqnutAZ

SOLUTION: eqnu

PROBLEM: aZcGMvzBhazkCIFqpVe, AOljBvzBhazkWXeTuA

SOLUTION:
vzBhazk