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

ftvxfhsnJEygzV, JYxSfhsnJnIqkW
fhsnJ

XbjDHRCWxdPbhibUKn, SrpuPDHRCWxdPbKPWEXNWbZ
DHRCWxdPb

XzssqQWAlOzvckLQEhI, IQoRCjPsqQWAlOzrIhjzNwV

sqQWAlOz