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

SOLUTION: ffTbIbBrcH

PROBLEM: RMurrwPjlfG, QBKrrwPDkTM

SOLUTION: rrwP

PROBLEM: DZfOjrQffR, CXOjrQQc

SOLUTION:
OjrQ