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

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

#define nmax 21

int n, op;

struct nod {
	int apW;
	int apL;
	nod *next[26];
};
nod *root;

inline void init(nod *&root) {
	root = new nod;
	root->apW = 0;
	root->apL = 0;
	memset(root->next, 0, sizeof(root->next));
}

inline void insert_trie(nod *root, char a[], int n) {
	for (int i = 1; i <= n; ++i) {
		if (root->next[a[i] - 'a'] == NULL) 
			init(root->next[a[i] - 'a']);
		root = root->next[a[i] - 'a'];
		++root->apL;
	}
	++root->apW;
}

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

char w[nmax];

inline void erase(nod *&root, int i) {
	if (i == n + 1) {
		--root->apW;
		--root->apL;
		if (!root->apL) {
			delete root;
			root = NULL;
		}
		return;
	}
	erase(root->next[w[i] - 'a'], i + 1);
	--root->apL;
	if (!root->apL) {
		delete root;
		root = NULL;
	}
}

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

int main() {
	init(root);
	while (fin >> op) {
		fin >> (w + 1);
		n = strlen(w + 1);
		if (op == 0)
			insert_trie(root, w, n);
		if (op == 1) 
			erase(root, 1);
		if (op == 2) 
			fout << query_ap(root, w, n) << '\n';
		if (op == 3) 
			fout << prefix(root, w, n) << '\n';
	}
	return 0;
}