#!/usr/bin/env python3

import sys
sys.stdout = open('hashuri.out', 'w')

with open('hashuri.in', 'r') as f:
    h = set()
    for _ in range(int(f.readline())):
        op = tuple(map(int, f.readline().split()))
        if op[0] == 1: h.add(op[1])
        elif op[0] == 2: h.discard(op[1])
        else: print(1 if op[1] in h else 0)