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

Answer: mQuy


Question: vISTrmBMpQyanUTSXUCm, dJGyOHMpQyanUTpSb

Answer: MpQyanUT


Question: BsbcWnXi, XPbcWWki

Answer:
bcW