#include <fstream>
using namespace std;

ifstream fin("trie.in");
ofstream fout("trie.out");

struct trie
{
	int nrf = 0, nrc = 0;
	trie *f[26] = {};
};

trie *t = new trie;

void pune (trie *nod, char *c)
{
	if (c[0] == '\0')
		nod->nrc++;
	else
	{
		if (nod->f[c[0]-'a'] == NULL)
		{
			nod->f[c[0]-'a'] = new trie;
			nod->nrf++;
		}
		pune (nod->f[c[0]-'a'], c+1);
	}
}

bool sterge (trie *nod, char *c)
{
	if (c[0] == '\0')
		nod->nrc--;
	else
	{
		if (sterge (nod->f[c[0] - 'a'], c + 1) == 1)
		{
			nod -> f[c[0]-'a'] = NULL;
			nod -> nrf--;
		}
	}
	
	if (nod -> nrc == 0 && nod -> nrf == 0 && nod != t)
	{
		delete nod;
		return 1;
	}
	return 0;
}

int nrap (trie *nod, char *c)
{
	if (c[0] == '\0')
		return nod -> nrc;
	else
	{
		if (nod -> f[c[0] - 'a'] != NULL)
			return nrap (nod->f[c[0]-'a'], c+1);
		return 0;
	}
}

int pref (trie *nod, char *c)
{
	if (c[0] == '\0' || nod -> f[c[0]-'a'] == NULL)
		return 0;
	return 1 + pref(nod->f[c[0]-'a'], c+1);
}

int main()
{
	int x;
	char c[21];
	while (fin >> x >> c)
	{
		if (x == 0)
			pune(t, c);
		else if (x == 1)
			sterge(t, c);
		else if (x == 2)
			fout << nrap (t, c) << '\n';
		else
			fout << pref (t, c) << '\n';
	}
	return 0;
}