#include <bits/stdc++.h>
#define nmax 16000
#define pb push_back
using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
int n,i,max1,cer,nr;
long long x;
set <long long > m;
set <long long >  ::iterator it;
int main()
{
 f>>n;
 for(i=1;i<=n;i++)
 {
     f>>cer>>x;
     if(cer==1)
        m.insert(x);
     if(cer==2)
     {
         m.erase(x);
     }
     if(cer==3)
     {
         g<<(m.find(x)!=m.end())<<'\n';
     }
 }
    return 0;
}