#include <fstream>
using namespace std;

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

struct Nod
{
	int Nr, NrSons;
	Nod * Son[26];
	Nod()
	{
		Nr = NrSons = 0;
		for(int i = 0; i < 26; ++i)
			Son[i] = 0;
	}
};
Nod * Trie = new Nod;

void Insert(char * S, Nod * p)
{
	if(!(*S))
	{
		p->Nr++;
		return;
	}
	int Index = *S - 'a';
	if(!(p->Son[Index]))
	{
		p->Son[Index] = new Nod;
		p->NrSons++;
	}
	Insert(S + 1, p->Son[Index]);
}

bool Delete(char * S, Nod * p)
{
	if(!(*S)) p->Nr--;
	else
	{
		int Index = *S - 'a';
		if(Delete(S + 1, p->Son[Index]))
		{
			p->Son[Index] = 0;
			p->NrSons--;
		}
	}
	if(p->Nr == 0 && p->NrSons == 0 && p != Trie)
	{
		delete p;
		return 1;
	}
	return 0;
}

int Print(char * S, Nod * p)
{
	if(!(*S)) return p->Nr;
	int Index =  *S - 'a';
	if(p->Son[Index])
		return Print(S + 1, p->Son[Index]);
	else return 0;
}

int Prefix(char * S, Nod * p, int k)
{
	int Index = *S - 'a';
	if(!(*S) || !(p->Son[Index])) return k;
	else return Prefix(S + 1, p->Son[Index], k+1);;
}

int main()
{
	char Line[25];
	while(in.getline(Line, 25))
	{
		if(Line[0] == '0')
			Insert(Line + 2, Trie);
		else if(Line[0] == '1')
			Delete(Line + 2, Trie);
		else if(Line[0] == '2')
			out << Print(Line + 2, Trie) << '\n';
		else if(Line[0] == '3')
			out << Prefix(Line + 2, Trie, 0) << '\n';
	}
	return 0;
}