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

Input: Consider Input: iaXeqfIrYKxPJRXxfSm, rIYKxPJRXxfsjVsqe

Output: YKxPJRXxf


Input: Consider Input: yRhCObvPZYoKUoQnyaatR, NHzLJYPZYoKUoQnJnIsZxC

Output: PZYoKUoQn


Input: Consider Input: MqSQJjBJlik, shwYQJjBJlNYdZ


Output: QJjBJl