spoj#LSQF. Longest Square Factor
Longest Square Factor
Given a string x, the string obtained by concatenating x to itself is sometimes called the square of x.
Given a string s, output the longest string x such that its square is a substring of s. If you find more than one solution, output the lexicographically smallest.
Input
The first and only line of input contains a string s (consisting only of lowercase letters of the english alphabet). The length of s is less than or equal to 105.
Output
To the first line of output print the length of the string x.
To the second line print the string x.
Such a string will always exist in the test data.
Example
Input: abcabc
Output: 3
abc