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

Q: lypuwWy, jRpuwcE

A: puw
****
Q: UmYbssMbmsXkKQuzNasLOib, EMqlbmsXkKQuzNcyHrpZXOQW

A: bmsXkKQuzN
****
Q: BjbxEKqUuSW, VCfxEKqUucf

A:
xEKqUu
****