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

[EX Q]: PShMbsbexXGlpBuMMDZZS, sVqGxSexXGlpBxuHXoI
[EX A]: exXGlpB

[EX Q]: HiEuutntEBpU, fdkqEuutntEBABdGZRND
[EX A]: EuutntEB

[EX Q]: mnMKHcYiW, YZRKHcYByy
[EX A]:
KHcY