fin = open("hashuri.in", "r")
fout = open("hashuri.out", "w")

Q = int(fin.readline())

set = {""}
set.clear()

for i in range(Q):
    input = fin.readline()
    op, no = map(int, input.split())
    
    if op == 1:
        set.add(no)
    elif op == 2:
        set.discard(no)
    else:
       fout.write(str(int(no in set)))
       fout.write('\n')

fin.close()
fout.close()