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.
def year(n):
    while n < 9000:
        n += 1
        s = str(n)
        ls = []
        for i in s:
            ls.append(i)
        if len(set(ls)) == 4:
            print(n)
            break
    return

a = int(input())
year(a)
