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

SOLUTION: jDoJDdRNN

PROBLEM: iYuUgULgqcAgd, kRNUgULgqFv

SOLUTION: UgULgq

PROBLEM: PMzhzKddhx, FFINfzhzKdOO

SOLUTION:
zhzKd