In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

[EX Q]: ilgSzrcUKLTNLJbMKMKSt, hFXIuUKLTNLJbMKWxSCkDjY
[EX A]: UKLTNLJbMK

[EX Q]: lypuwWy, jRpuwcE
[EX A]: puw

[EX Q]: KjJTjD, bbJTzH
[EX A]:
JT