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

Input: Consider Input: XZslQqrShfCXRXyHrFVq, BtOQgQqrShfCXRRCRbMvXPM

Output: QqrShfCXR


Input: Consider Input: sEYtoQlG, XIstoQQPw

Output: toQ


Input: Consider Input: yTCUxxKmodVraJrK, tYxxKmodVrypsa


Output: xxKmodVr