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

Input: Consider Input: euQWhCovKplukMYznXcD, XAfMhKdzhCovKplukMcMlSuBw

Output: hCovKplukM


Input: Consider Input: FgQsxN, UMQsIa

Output: Qs


Input: Consider Input: iAGsHj, PtGsoN


Output: Gs