fin = open("hashuri.in", "r")
fout = open("hashuri.out", "w")
s = set()
sir = fin.readline()
n = int(sir)
for i in range(n):
    sir = fin.readline()
    l = list([int(x) for x in sir.split()])
    op, x = l
    if op == 1:
        s.add(x)
    elif op == 2:
        s.discard(x)
    else:
        if x in s:
            fout.write("1\n")
        else:
            fout.write("0\n")
fin.close()
fout.close()