Beautiful Year

给定一个年份n，输出**大于**n的第一个**四位数字都不相同的**年份。 感谢@引领天下 提供的翻译

It seems like the year of 2013 came only yesterday. Do you know a curious fact? The year of 2013 is the first year after the old 1987 with only distinct digits. Now you are suggested to solve the following problem: given a year number, find the minimum year number which is strictly larger than the given one and has only distinct digits.

The single line contains integer $ y $ $ (1000<=y<=9000) $ — the year number.

Print a single integer — the minimum year number that is strictly larger than $ y $ and all it's digits are distinct. It is guaranteed that the answer exists.

1987

2013

2013

2014