with open("hashuri.in", "r") as f, open("hashuri.out", "w") as g:
    n = int(next(f))
    dic = {}
    while n:
        n -= 1
        t, x = (int(i) for i in next(f).split())
        if t == 1:
            dic[x] = 1
        elif t == 2:
            if x in dic:
                del dic[x]
        else:
            g.write("1\n" if x in dic else "0\n")