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

SOLUTION: xgz

PROBLEM: TvNVpHLPYjBCeUpyxlzFZ, tgKdPKVYjBCeUpyPK

SOLUTION: YjBCeUpy

PROBLEM: GghHejxdRCdASOYzgV, tijexdRCdADc

SOLUTION:
xdRCdA