#include <bits/stdc++.h>

using namespace std;

int n;
int main()
{
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);

    scanf("%d",&n);
    set<int> S;
    for(int i=1;i<=n;i++){
        short ch;
        int number;
        scanf("%d%d",&ch,&number);


        switch(ch){
        case 1:
            S.insert(number);
            break;
        case 2:
            S.erase(number);
            break;
        case 3:
            if(S.count(number))
                printf("1\n");
            else
                printf("0\n");
            break;
        default:
            break;
        }
    }


    return 0;
}