#include <bits/stdc++.h>

using namespace std;

unordered_set<int> M;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
int n,x,y;

int main()
{
    fin>>n;
    for(int i=1;i<=n;i+=1)
    {
        fin>>x>>y;
        if(x==1) M.insert(y);
        else if(x==2) M.erase(y);
        else fout<<(M.find(y)!=M.end());
    }
    return 0;
}