#include<fstream>
#include<cstring>
using namespace std;

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

int op, len;
char c[40];

struct Trie{
	int freq, words;
	Trie *son[27];
	Trie()
	{
		int i;
		for (i = 0; i <= 26; ++i)
			son[i] = NULL;
		freq = words = 0;
	}
};
Trie *T;
void Insert(Trie *nod)
{
	int i, next;
	for (i = 0; i<len; i++)
	{
		next = c[i] - 'a';
		if (nod->son[next] == NULL)
			nod->son[next] = new Trie;
		nod = nod->son[next];
		nod->freq++;
	}
	nod->words++;
}

void Delete(Trie *nod)
{
	int i, next;
	for (i = 0; i<len; i++)
	{
		next = c[i] - 'a';
		nod = nod->son[next];
		nod->freq--;
	}
	nod->words--;
}

int Search(Trie *nod)
{
	int i, next;
	for (i = 0; i<len; i++)
	{
		next = c[i] - 'a';
		if (nod->son[next] == NULL)
			return 0;
		nod = nod->son[next];
	}
	return nod->words;
}

int Prefix(Trie *nod)
{
	int i, next, sol = 0;
	for (i = 0; i<len; i++)
	{
		next = c[i] - 'a';
		if (nod->son[next] == NULL)
			break;
		nod = nod->son[next];
		if (nod->freq>0) sol++;
		else break;
	}
	return sol;
}

int main()
{
	T = new Trie;
	while (fin >> op >> c)
	{
		len = strlen(c);
		switch (op)
		{
			case 0: Insert(T); break;
			case 1: Delete(T); break;
			case 2: fout << Search(T) << '\n'; break;
			case 3: fout << Prefix(T) << '\n'; break;
		}
	}
	return 0;
}