#include <fstream>
#include <iostream>
#include <stdio.h>
#include <unordered_map>
using namespace std;
 
 
unordered_map <unsigned int, int> mMap;
int queries;
 
int main()
{
    freopen("hashuri.in", "r", stdin);
	freopen("hashuri.out", "w", stdout);
    int type, param, cnt = 0;
    scanf("%d",&queries);
    for(int i = 0 ; i < queries; i++)
    {
        scanf("%d%d",&type,&param);
        if(type == 1)
            mMap[param] = ++cnt;
        if(type == 2)
            mMap.erase(param);
        if(type == 3)
            printf("%d\n",mMap.find(param) != mMap.end());
    }
 
    return 0;
}