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

JjEQVKijeyEQ, dwSVKijeywCTvb
VKijey

sRTQgRgRUjEooapKdR, vzsBgRUjEooLBkYeH
gRUjEoo

mzQBntyckkfF, PKNChUntyckkvbT

ntyckk