Problems
One morning, completely by chance, Mirko found a positive integer N in the middle of the street. Since Mirko adores the number 30, he wants to know the maximum multiple of the number 30 that can be obtained by shuffling the digits of the number he found in the street.
Help our hero and write a programme that calculates that number (if it exists).
Input
The first and only line of input contains the integer N, consisting of at most 105 digits.
Output
The first and only line of output must contain the required number from the task, if it exists. If it doesn’t exist, output -1.
Example #1
30
30
Example #2
102
210
Example #3
2931
-1
Tag
Source
COCI 2014/2015 contest4 1
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