f=open("hashuri.in",'r')
g=open("hashuri.out",'w')
n=int(f.readline())
l=list()
def add(li,el):
    li.append(el)

def remove(li,el):
    li.pop(li.index(el))

def ver(li,el):
    if el in li:
        g.write('1' + '\n')
    else:
        g.write('0' + '\n')

for i in range(n):
    line=f.readline().split()
    a=int(line[0])
    b = int(line[1])

    if a==1:
        if b not in l:
            add(l,b)
    elif a==2:
        if b in l:
            remove(l,b)
    else:
        ver(l,b)

f.close()
g.close()