# 3레벨 코딩테스트 고득점 Kit 여행경로
from copy import deepcopy
def solution(tickets):
tickets.sort(key=lambda x: (x[0]))
result = []
def dfs(road, ticket):
if len(road) == len(tickets) + 1:
result.append(deepcopy(road))
return
for idx in range(len(ticket)):
if road[-1] == ticket[idx][0]:
temp = ticket[idx]
road.append(ticket[idx][1])
del ticket[idx]
dfs(road, ticket)
road.pop()
ticket.insert(idx, temp)
dfs(["ICN"], deepcopy(tickets))
result.sort(key=lambda x: x)
return result[0]