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

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

int i, j, n;
int op;

char a[26];

struct nod {
	int w;
	int l;
	nod *next[26];
};
nod *R;

void init(nod *&R) {
	R = new nod;
	R->w = 0;
	R->l = 0;
	memset(R->next, 0, sizeof(R->next));
}

void insert(nod *R, char a[], int n) {
	for (int i = 1; i <= n; ++i) {
		if (R->next[a[i] - 'a'] == NULL) 
			init(R->next[a[i] - 'a']);
		R = R->next[a[i] - 'a'];
		++R->l;
	}
	++R->w;
}

int nrAp(nod *R, char a[], int n) {
	for (int i = 1; i <= n; ++i) {
		if (R->next[a[i] - 'a'] == NULL) return 0;
		R = R->next[a[i] - 'a'];
	}
	return R->w;
}

void erase(nod *&R, int i) {
	if (i == n + 1) {
		--R->l;
		--R->w;
		if (R->l == 0) {
			delete R;
			R = NULL;
		}
		return;
	}
	erase(R->next[a[i] - 'a'], i + 1);
	--R->l;
	if (R->l == 0) {
		delete R;
		R = NULL;
	}
}

int prefix(nod *R, char a[], int n) {
	for (int i = 1; i <= n; ++i) {
		if (R->next[a[i] - 'a'] == NULL) return i - 1;
		R = R->next[a[i] - 'a'];
	}
	return n;
}

int main() {
	init(R);
	while ((fin >> op)) {
		fin >> (a + 1);
		n = strlen(a + 1);
		if (op == 0) {
			insert(R, a, n);
			continue;
		}
		if (op == 1) {
			erase(R, 1);
			continue;
		}
		if (op == 2)
			fout << nrAp(R, a, n) << '\n';
		else 
			fout << prefix(R, a, n) << '\n';
	}
	return 0;
}