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

SOLUTION: ns

PROBLEM: sOSXbnluNuvwMETKda, JzXbnluNuvyeVHO

SOLUTION: XbnluNuv

PROBLEM: eYJybCINeJ, jQPybCIdXmf

SOLUTION:
ybCI