instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
AxAmDG, LTAmEV
answer:
Am


question:
uDaqoOpUtLDdTGTO, ncIgBjDPqoOpUtLDdTNtiEyarDO
answer:
qoOpUtLDdT


question:
CNyInsdWZR, aiucyInsIU
answer:

yIns