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

SOLUTION: ddewrN

PROBLEM: oZNKLmfxecDfkXEGFkRBYk, tReqkiExecDfkXEGtNZpJVRxC

SOLUTION: xecDfkXEG

PROBLEM: bmsrkXGb, GcarkXOZF

SOLUTION:
rkX