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

JXnHYuZvAYK, zhUYuZvASGhd
YuZvA

oKZCAErEMqzODnkcNqxVdoBOC, yHzRJuSqzODnkcNqxExr
qzODnkcNqx

xxocGoSwCM, OPYEocGoDca

ocGo