#include <iostream>
#include <fstream>
#include <unordered_map>
using namespace std;

unordered_map <int,int> ump;

ifstream f("hashuri.in");
ofstream g("hashuri.out");

int n,x,y,i;

int main()
{
    f>>n;
    for(i=1;i<=n;i++)
    {
        f>>x>>y;
        if(x==1){
        ump[y]=1;}
        else
        if(x==2){
        if(ump[y]==1)
        ump[y]=0;
        }
        else
        if(x==3)
            if(ump[y]==1)
                g<<y<<endl;
    }
    return 0;
}