Longest Common Substring

n strings are given. Find their common substring of maximum length. It is known that its length is positive.

Input

First line contains the number of strings n (1 ≤ n ≤ 10^5). Each of the next n strings contains one line of lowercase Latin letters. The total sum of strings' length is no more than 10^5.

Output

Print the common substring of maximum length.

Examples