#include <fstream>
#include <string>
#define f(a) ((a) - 'a')
using namespace std;

typedef struct Trie * Arbore;
const int SIGMA = 27;

struct Trie
{
	int count; /// cate se opresc in nod
	int count_fii[SIGMA];
	Arbore fii[SIGMA];
	Trie()
	{
		for (int i = 0; i < SIGMA; i++)
			count_fii[i] = 0, fii[i] = 0;
		count = 0;
	}
	~Trie()
	{
		for (int i = 0; i < SIGMA; i++)
			if (fii[i])
				delete fii[i];
	}
};

inline void add(string &s);
inline void erase(string &s);
inline int count(string &s);
inline int l_pref(string &s);

Arbore k;

int main()
{
	k = new Trie();
	string s;
	char op;
	ifstream in("trie.in");
	ofstream out("trie.out");
	while (in >> op >> s) {
		switch (op) {
		case '0':
			add(s);
			break;
		case '1':
			erase(s);
			break;
		case '2':
			out << count(s) << '\n';
			break;
		default:
			out << l_pref(s) << '\n';
		}
	}
	return 0;
}

void add(string & s)
{
	Arbore x = k;
	int p;
	for (const char &c : s) {
		p = f(c);
		if (!x->fii[p])
			x->fii[p] = new Trie();
		x->count_fii[p]++;
		x = x->fii[p];
	}
	x->count++;
}

void erase(string & s)
{
	Arbore x = k;
	int p;
	for (const char &c : s) {
		p = f(c);
		if (x->count_fii[p] == 1) {
			delete x->fii[p];
			x->fii[p] = 0;
			x->count_fii[p] = 0;
			return;
		}
		if (!x->fii[p])
			return;

		x->count_fii[p]--;
		x = x->fii[p];
	}
	x->count--;
}

int count(string & s)
{
	Arbore x = k;
	int p;
	for (const char &c : s) {
		p = f(c);
		if (!x->fii[p])
			return 0;
		x = x->fii[p];
	}

	return x->count;
}

int l_pref(string & s)
{
	Arbore x = k;
	int l = 0, p;
	for (const char &c : s) {
		p = f(c);
		if (x->fii[p]) {
			l++;
			x = x->fii[p];
		}
		else
			break;
	}
	return l;
}