#include <iostream>
#include <cstring>
#include <vector>
#include <cmath>
using namespace std;
int i;
vector<vector<long long>> set(1000005, vector<long long>());

void ins(long long x)
{
	int num = abs(x % 1000003);
	for (i = 0; i < set[num].size(); i++)
	{
		if (set[num][i] == x) {
			return;
		}
	}
	set[num].push_back(x);

}

void del(long long x)
{
	int num = abs(x % 1000003);
	for (i = 0; i < set[num].size(); i++)
	{
		if (set[num][i] == x) {
			set[num].erase(set[num].begin() + i);
			break;
		}
	}
}

bool exi(long long x)
{
	int num = abs(x % 1000003);
	for (i = 0; i < set[num].size(); i++)
	{
		if (set[num][i] == x) {
			return true;
		}
	}
	return false;
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	freopen("set.in", "r", stdin);
	freopen("set.out", "w", stdout);
	string s;
	long long x;
	while (cin >> s)
	{
		if (s == "insert") {
			cin >> x;
			ins(x);
		}
		else if (s == "delete") {
			cin >> x;
			del(x);

		}
		else {
			cin >> x;
			if (exi(x)) cout << "true\n";
			else cout << "false\n";
		}
		/*for (int j = 0; j < set.size(); j++)
		{
			for (int h = 0; h < set[j].size(); h++)
				cout << set[j][h] << " " << j << " " << h << "\n";
		}*/
	}
	return 0;
}
/*
delete 1
delete 2
insert 2
insert 5
insert 1000005
insert 3
exists 2
exists 4
insert 2
delete 2
delete 2
delete 2
exists 2
*/