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

GnElFKBIoYmAdvz, GrElFKBIoMo
ElFKBIo

uDaqoOpUtLDdTGTO, ncIgBjDPqoOpUtLDdTNtiEyarDO
qoOpUtLDdT

fqRQIpFj, hlRQIuBV

RQI