TASK DEFINITION: In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
PROBLEM: lMRuEThD, wqQRuEKp

SOLUTION: RuE

PROBLEM: bmZKWkYPqugcvzbHykblPzQLhK, tPUzKqugcvzbHypzk

SOLUTION: qugcvzbHy

PROBLEM: hoEXRWilHjXkvYaHnV, FwLRWilHjXklSxYJZ

SOLUTION:
RWilHjXk