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

Ex Input:
XpFCxFOgTTNCnQzMnVPV, FMqzdOwgTTNCnQzedorxVPe

Ex Output:
gTTNCnQz


Ex Input:
XqyPjqNZDEK, EfwPjqNgjIP

Ex Output:
PjqN


Ex Input:
vISTrmBMpQyanUTSXUCm, dJGyOHMpQyanUTpSb

Ex Output:

MpQyanUT