https://programmers.co.kr/learn/courses/30/lessons/64065
def solution(s):
sets = get_sets(s)
sets.sort(key=lambda x: len(x))
answer = list(sets[0])
for i in range(1, len(sets)):
for j in range(i, len(sets)):
sets[j].remove(list(sets[i-1])[0])
answer.append(list(sets[i])[0])
return answer
def get_sets(s):
temp = s[2:-2].split('},{')
sets = [set(map(int, t.split(','))) for t in temp]
return sets