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

SOLUTION: DQjzAIsn

PROBLEM: ilgSzrcUKLTNLJbMKMKSt, hFXIuUKLTNLJbMKWxSCkDjY

SOLUTION: UKLTNLJbMK

PROBLEM: iOWzkggTreHfUOtH, svQkggTreHfUmM

SOLUTION:
kggTreHfU