In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

Ex Input:
sRTQgRgRUjEooapKdR, vzsBgRUjEooLBkYeH

Ex Output:
gRUjEoo


Ex Input:
UldKHMpUYADGfEUGcSon, nPHMpUYADGfEKqHCLPmL

Ex Output:
HMpUYADGfE


Ex Input:
trVCnwRGrYWRkWmsCguFDLzN, WBDizAZwRGrYWRkWmctlzpfxtmq

Ex Output:

wRGrYWRkWm