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

iaXeqfIrYKxPJRXxfSm, rIYKxPJRXxfsjVsqe
YKxPJRXxf

QaxEaxdouNyyvNAn, wRjWSaxdouNyyrriQiG
axdouNyy

JgxGdGEDFAwE, uGItxGdGEDgb

xGdGED