Lexicographically Largest String

You are given a string s consisting of lowercase English letters. You can perform an operation any number of times. In each operation, you can replace any character in the string with the lexicographically larger character that appears in s.

Your task is to transform s into the lexicographically largest possible string. It can be proved that the optimal strategy is to choose the maximum character in s and replace every character with that maximum letter. In other words, if m is the maximum letter in s and n is the length of the string, the result is:

$$ m^n $$

For example, if s = "abac", then the maximum letter is c and the answer is cccc.

inputFormat

The input consists of a single string s provided from the standard input. The string may be empty and consists of lowercase English letters only.

outputFormat

Output the lexicographically largest string possible (i.e. the maximum character repeated n times, where n is the length of s). Print the result to standard output.

abac

cccc