#include <iostream>
#include <fstream>
#include <string>
#include <vector>
using namespace std;

ifstream fin("set.in");
ofstream fout("set.out");
vector <int> HashTable(1000001);

int GetHash(int element)
{
	int Hash = abs((int)(element % 1000001));
	return Hash;
}
void Insert(int element)
{
	int Hash = GetHash(element);
	if (HashTable[Hash] == NULL)
		HashTable[Hash] = element;
}
void Exists(int element)
{
	int Hash = GetHash(element);
	if (HashTable[Hash] != NULL)
		fout << "true\n";
	else
		fout << "false\n";
}
void Delete(int element)
{
	int Hash = GetHash(element);
	HashTable[Hash] = NULL;
}
int main() {
	string s;
	int element;
	while (fin >> s)
	{
		switch (s[0])
		{
		case 'i':
		{
			fin >> element;
			Insert(element);
			break;
		}
		case 'e':
		{
			fin >> element;
			Exists(element);
			break;
		}
		case 'd':
		{
			fin >> element;
			Delete(element);
			break;
		}
		}
	}
	return 0;
}