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

using namespace std; 

set<int> A;

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

	for(scanf("%d", &N); N; N--){
		scanf("%d %d", &x, &y);
		if(x == 1){
			A.insert(y);
			continue;
		}

		if(x == 2){
			A.erase(y);
			continue;
		}
		
		printf("%d\n", A.find(y) != A.end()); 
	}

	return 0;
}