f = open("hashuri.in", "r")
g = open("hashuri.out", "w")
a = {}
n = int(f.readline())
data = f.readlines()
for line in data:
    word = line.split()
    t = int(word[0])
    x = int(word[1])
    if t == 1:
        a[x] = x
    elif t == 2:
        if x in a:
            del a[x]
    elif x in a:
        g.write("1\n")
    else:
        g.write("0\n")