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

SOLUTION: PjqN

PROBLEM: oDdulHNcCdgbRGxiBTxM, kDcCdgbRGnsJlvas

SOLUTION: cCdgbRG

PROBLEM: MIgdGdAtrymJnurWN, JptfbPRtrymJnuLSsIPAS

SOLUTION:
trymJnu