Problems
The extra digits
The extra digits
In natural number \textbf{N} struck out some of his figures so as to obtain the largest natural number with different digits. What is this number?
\InputFile
Integer \textbf{N }(\textbf{1 }≤\textbf{ N }≤\textbf{ 10^100}).
\OutputFile
The answer to the problem.
Input example #1
32142341
Output example #1
4231