instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
XMtSwZVAHsNYhbyDm, asAVAHsNYhSPuNLrV
answer:
VAHsNYh


question:
wCfNCfxvLRAxBstRTwMSqTn, AhwxfFNCfxvLRAxBrNtf
answer:
NCfxvLRAxB


question:
jDDVniqAkbJPkDWtKw, wKNBNllsNDVniqAkbJmWuLBx
answer:

DVniqAkbJ