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

JjEQVKijeyEQ, dwSVKijeywCTvb
VKijey

SJIkEibGrqcrOBgGjYjJc, EervOGrqcrOBgGJZyx
GrqcrOBgG

dQwLnYhvkGkppAQwsvldd, xkkGkppAQwsiDRwIS

kGkppAQws