#include <iostream>
#include <cstdio>
#include <set>
using namespace std;
set<int>a;
int i,n,o,x;
int main()
{
   freopen("hashuri.in","r",stdin);
   freopen("hashuri.out","w",stdout);
   scanf("%d",&n);
   for(i=1;i<=n;++i)
   {
       scanf("%d %d ",&o ,&x);
       if (o==1) {a.insert(x);continue;}
       else if (o==2) {a.erase(x);continue;}
        printf("%d\n",a.find(x)!=a.end());
   }
    return 0;
}