// https://www.infoarena.ro/problema/trie

// trie clasic cu copii pe array de 26
// pass = cate cuvinte trec prin nod (pentru prefix si pentru stergerea nodurilor ramase libere)
// cnt  = cate cuvinte se termina exact in nod
// operatii: 0 = adauga, 1 = sterge, 2 = numara aparitiile, 3 = lungimea celui mai lung prefix comun

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

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

struct node {
    node *ch[26];
    int cnt;
    int pass;
};

node *make_node() {
    node *n = new node;
    for (int i = 0; i < 26; i++) n->ch[i] = nullptr;
    n->cnt = 0;
    n->pass = 0;
    return n;
}

void add(node *root, const string &w) {
    node *p = root;
    for (char c : w) {
        int k = c - 'a';
        if (!p->ch[k]) p->ch[k] = make_node();
        p = p->ch[k];
        p->pass++;
    }
    p->cnt++;
}

void erase(node *root, const string &w) {
    node *path[22];
    int idx[22];
    node *p = root;
    int d = 0;
    for (char c : w) {
        int k = c - 'a';
        path[d] = p;
        idx[d] = k;
        p = p->ch[k];
        d++;
    }
    p->cnt--;
    // scadem pass de jos in sus si stergem nodurile prin care nu mai trece niciun cuvant
    for (int i = d - 1; i >= 0; i--) {
        node *child = path[i]->ch[idx[i]];
        child->pass--;
        if (child->pass == 0) {
            delete child;
            path[i]->ch[idx[i]] = nullptr;
        }
    }
}

int count_word(node *root, const string &w) {
    node *p = root;
    for (char c : w) {
        int k = c - 'a';
        if (!p->ch[k]) return 0;
        p = p->ch[k];
    }
    return p->cnt;
}

int longest_prefix(node *root, const string &w) {
    node *p = root;
    int len = 0;
    for (char c : w) {
        int k = c - 'a';
        if (!p->ch[k]) break;
        p = p->ch[k];
        len++;
    }
    return len;
}

int main() {
    node *root = make_node();
    int op;
    string w;
    while (fin >> op >> w) {
        if (op == 0) add(root, w);
        else if (op == 1) erase(root, w);
        else if (op == 2) fout << count_word(root, w) << '\n';
        else if (op == 3) fout << longest_prefix(root, w) << '\n';
    }
    return 0;
}