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

Q: YlhtTQgHiffTbIbBrcHMqFKCdWz, HyregFgMffTbIbBrcHYUnnQvGlx

A: ffTbIbBrcH
****
Q: CCzKRbuEAmN, qTLzKRbuhEqq

A: zKRbu
****
Q: BICndZkjoSidWivWATvtqsS, FzVWjoSidWivFaQhkRT

A:
joSidWiv
****