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

SOLUTION: zLSz

PROBLEM: KfjqnJLciTXqkJK, yqfRcfqnJLcisSB

SOLUTION: qnJLci

PROBLEM: kQSPVPxoCJozSm, fXcCHPxoCJrWIyQ

SOLUTION:
PxoCJ