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

SOLUTION: nxmaQUr

PROBLEM: FQAznAuFjoBKRKB, hPmtFFPnuAznAuFjoBKTgkeJyjcd

SOLUTION: AznAuFjoBK

PROBLEM: XHbcAvoXDGFZ, APAvoXgbX

SOLUTION:
AvoX