## Problem A. As simple as it gets ≡

 Author: A. Klenin Time limit: 1 sec Input file: input.txt Memory limit: 64 Mb Output file: output.txt

### Statement

Let us define that a positive integer A is simpler than a positive integer B if the decimal representation of A requires less different digits than the decimal representation of B.

For example, number 55 is simpler than 12 which in turn is simpler than 123.

Your program will be given a number N and must find the largest integer X such that X < N and X is simpler than N.

### Input file format

Input file contains integer N.

### Output file format

Output file must contain integer X. If there is no integer simpler than N, output file must contain 0 (zero).

1 ≤ N ≤ 231 − 1

### Sample tests

No. Input file (input.txt) Output file (output.txt)
1
111
0
2
765437654
765377777

0.040s 0.008s 13