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

Example Input: yxJxNRLEnKGHziJtfb, KfReWhEnKGHzitzfPWzK
Example Output: EnKGHzi

Example Input: inquDFuJxtBaaFGCaRzO, NYcnWDuDFuJxtBafxZWCUw
Example Output: uDFuJxtBa

Example Input: iNdWSzBOhvVJEZECbcpoqr, aTikAutqhvVJEZECvGRK
Example Output:
hvVJEZEC