### Indian National Olympiad in Informatics

### Online Programming Contest, 15-16 April 2006

### Basic Division

Problem 1: Repetition-free numbers, *(K Narayan Kumar, CMI)*

A repetition-free number is one in which each digit
{1,2,3,…,9} appears at most once and the digit 0 does not
appear. A repetition-free number can have at most nine digits, but
may also have fewer than nine digits. Some examples of
repetition-free numbers are 9, 32, 489, 98761 and 983245.

You will be given an integer *N* with at most nine digits.
Your task is to print out the smallest repetition-free number bigger
than *N*. For example, for 99 the answer is 123, for 881 the
answer is 891, and for 133 the answer is 134.

Input format

A single line with a single integer with at most 9 digits.

Output format

A single line containing the smallest repetition-free number bigger
than the given number. If there is no repetition-free number bigger
than the given number, print 0.

Example

We now illustrate the input and output formats using the example
described above.

Sample input

99

Sample output

123