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

SOLUTION: xr

PROBLEM: mjCEUoPmeKbvCgUtUL, SrHtrPmeKbvYpQAVp

SOLUTION: PmeKbv

PROBLEM: kuyTdtKin, NbmyTdtuec

SOLUTION:
yTdt