백준 11723번 파이썬

import sys

n=int(sys.stdin.readline())

s= set()

for _ in range(n):

    a=sys.stdin.readline().split()

    if len(a)==1:

        if a[0]=="all":

            s=set([x for x in range(1,21)])

        else:

            s=set()

    else:

        p=a[0]

        q=a[1]

        q=int(q)

        if p =="add":

            s.append(q)

            #s.add(q)

        elif p == "remove":

            s.discard(q)

        elif p == "check":

            print(1 if q in a else 0)

        elif p == "toggle":

            if q in s:

                s.discard(q)

            else:

                s.add(q)