Baekjoon-1038-감소하는 수

from itertools import combinations
N = int(input())

num = []
for i in range(1,11): # O(10)
    for comb in combinations(range(10),i): # maximum O(10C5) = O(112)
        comb = list(comb)
        comb = sorted(comb, reverse=True) # maximum n^2=O(100)
        num.append(int("".join(map(str,comb))))
# O(1e5) -> Brute-force

num = sorted(num)
if len(num)-1 < N:
    print(-1)
else:
    print(num[N])