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

TnHJcxtwcZ, XFdHJcxNKw
HJcx

xQcYRVFFqrVAMsBm, VErcKZvcYRVFFqzKo
cYRVFFq

yHjCrnPHxM, EVOvCrnPHlNFzD

CrnPH