#include <iostream>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <list>
#include <unordered_set>

#define NMAX 1000005

int main()
{
    FILE *fin,*fout;
    fin=fopen("hashuri.in","r");
    fout=fopen("hashuri.out","w");

    std::unordered_set<int> hash; //nu merita ceva mai complicat :)
    int n,i,op,x;

    fscanf(fin,"%d",&n);
    for(i=0;i<n;i++) {
        fscanf(fin,"%d %d",&op,&x);
        if(op==1) hash.insert(x);
        if(op==2) hash.erase(x);
        if(op==3) fprintf(fout,"%d\n",hash.count(x));
    }

    fclose(fin);
    fclose(fout);

    return 0;
}