Divisibility by 15
Description
There is a string containing only decimal digit characters. The length of the string is between 1 and 1000. Using characters of the string, you have to construct the maximum number which divides by fifteen without remainder. Each character of the string may not be used more than once.
Input
The input contains a single line representing the source string.
Output
The output contains one line with the decimal representation of the maximum number. Leading zeroes should be omitted. If no number can be constructed, the output file has to contain a single word “impossible”.
020414200Source
Northeastern Europe 2004, Western Subregion