#include <iostream>
#include <stdio.h>
#include <map>
using namespace std;
map <int,int> M;
int N,nr,op,x;

int main()
{
    freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);
    scanf("%d",&N);
    for(int i=1;i<=N;i++)
    {
        scanf("%d %d",&op,&x);
        if(op==1)
            if(M.find(x)==M.end())
            M[x]=++nr;
        if(op==2)
            M.erase(x);
        if(op==3)
            printf("%d\n",M.find(x)!=M.end());
    }

}