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

SOLUTION: nplQZF

PROBLEM: lsNwypFwhKP, diEfLwypFwEKqCN

SOLUTION: wypFw

PROBLEM: xebFaSSYb, ikDFaSUDF

SOLUTION:
FaS