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

Q: OVZxWYzAAxG, rStOxWYzJeoC

A: xWYz
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Q: GBTHKtWUzK, ovVNKtWUmVJF

A: KtWU
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Q: aQsWeDkHudHxQKVLIr, xAMDlBkHudHxQKVWIuWKPGiZ

A:
kHudHxQKV
****