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 check_num(num):
    while True:
        num += 1
        num_str = str(num)
        num_set = set()
        
        for n in num_str:
            num_set.add(n)
        
        if len(num_set) == 4:
            return num
        else:
            num_set.clear()


print(check_num(int(input())))
