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

Q: CUlMsvov, iflMsSRp

A: lMs
****
Q: jdLbZSCzaAHGbNwILGmudOH, RdIPuEYJvUZSCzaAHGbNduLToRC

A: ZSCzaAHGbN
****
Q: BaFQxjha, hMQxjmBJ

A:
Qxj
****