instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
RinootTGLjbRGYznmBdH, oRMtTGLjbRGYzwEVHsjW
answer:
tTGLjbRGYz


question:
yITbYie, TlqTbYomH
answer:
TbY


question:
IsQvTcWtXHptpQBMBF, fHzSxWtXHptpQEOHj
answer:

WtXHptpQ