In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
--------
Question: xQcYRVFFqrVAMsBm, VErcKZvcYRVFFqzKo

Answer: cYRVFFq


Question: gXwuhXJrEdzGOmLSKdK, TohXJrEdzGavU

Answer: hXJrEdzG


Question: EsKYzcNYeBQPX, bQowyjYzcNYeBlGqBGJz

Answer:
YzcNYeB