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

Answer: RAbKdLu


Question: iupYjFXrrMqWzJSLUSwmEukHc, hqajjWrrMqWzJSLnF

Answer: rrMqWzJSL


Question: BdGPTeDfXXQlRbDc, geLWmfXXQlRbIr

Answer:
fXXQlRb