"""
    https://programmers.co.kr/learn/courses/30/lessons/42839
"""
# ********************** imcompleted status problem
def solution(n):
    n_length = len(n)
    num_set = set()
    for i in n:
        num_set.add(int(v))

        front_n = i - 1
        while front_n >= 0:
            pass

        end_n = i + 1
        while end_n < n_length:
            pass

if __name__ == '__main__':
    print(solution("17")) # 2
    print(solution("011")) # 2