#include<cstdio>
#include<map>
using namespace std;
map<int,int>M;
int n,nr,i,j,op,a;
FILE *f,*g;
int main(){
    f=fopen("hashuri.in","r");
    g=fopen("hashuri.out","w");
    fscanf(f,"%d",&n);
    for(i=1;i<=n;i++){
        fscanf(f,"%d%d",&op,&a);
        if( op == 1 ){
            if( M.find(a) == M.end() )
                M[a]=++nr;
        }
        else if( op == 2 )
            M.erase(a);
        else if( M.find(a) == M.end() )
            fprintf(g,"0\n");
        else
            fprintf(g,"1\n");
    }





    fclose(f);
    fclose(g);
    return 0;
}