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

fAsWQxuyBevvLogrSrgg, tmdBEUxuyBevvLogXjiMCbh
xuyBevvLog

cxYVucnmEQopeWHrPJ, jNnOaYVucnmEQoSE
YVucnmEQo

mhCvbSTPdOELaHaHufIfiBO, IiQepAPdOELaHaHZTZy

PdOELaHaH