#include <stdio.h>
#include <set>
#include <cstdlib>

using namespace std;

int n,op,x;
set <int> A;

int main()
{
    
    
    freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);
    
    for ( scanf("%d", &n); n ; n-- )
    {
        scanf("%d %d", &op, &x);
        if ( op == 1 )  A.insert(x);     
        if ( op == 2 )  A.erase(x);        
        if ( op == 3 )printf("%d\n", A.find(x) != A.end());
    }
 
    
    return 0;
}