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

Q: inquDFuJxtBaaFGCaRzO, NYcnWDuDFuJxtBafxZWCUw

A: uDFuJxtBa
****
Q: bmZKWkYPqugcvzbHykblPzQLhK, tPUzKqugcvzbHypzk

A: qugcvzbHy
****
Q: erUIuoKs, MUvIuoebX

A:
Iuo
****