백준-7785번(회사에 있는 사람)-python3

import sys

pe = {}

for _ in range(int(sys.stdin.readline())):
  p, c = sys.stdin.readline().rstrip().split()

  if c == 'enter':
    pe[p] = 'enter'
  else:
    if pe[p]:
      del pe[p]

for people in sorted(pe, reverse=True):
  print(people)