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

SOLUTION: toQ

PROBLEM: SyweIt, ILweip

SOLUTION: we

PROBLEM: JXmDZAsWz, QcmDZAAC

SOLUTION:
mDZA