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

SOLUTION: HcFUCflYUp

PROBLEM: WRfFDeZjIcpidmDxtaJcv, XMxWZjIcpidmlKga

SOLUTION: ZjIcpidm

PROBLEM: RrAiAiEPXUoWlKz, ZazEPXUoWjwxldx

SOLUTION:
EPXUoW