#include <bits/stdc++.h>
using namespace std;

#define ALFA 26

class Trie;

class Node {

 private:
    int visited, word_end;
    Node* son[ALFA];

 public:

    Node() {
        this->visited = 0;
        this->word_end = 0;

        for (auto& node : this->son)
            node = nullptr;
    }

    ~Node() {
        for (auto node : this->son)
            delete node;
    }

 friend Trie;
};

class Trie {

 private:
    Node* root = nullptr;
    int nr_words;
    const int offset = 'a';

 public:

    Trie() {
        this->nr_words = 0;
        this->root = new Node;
    }

    int countAparitions(string word) {

        Node* current = this->root;
        string :: iterator left = word.begin();
        string :: iterator right = word.end();

        for (left; left != right; left++) {
            int x = *left - offset;

            if (!current->son[x])
                return 0;

            current = current->son[x];
        }

        return current->word_end;
    }

    void insertWord(string word) {

        Node* current = this->root;
        string :: iterator left = word.begin();
        string :: iterator right = word.end();

        current->visited++;

        for (left; left != right; left++) {
            int x = *left - offset;

            if (!current->son[x])
                current->son[x] = new Node();

            current = current->son[x];
            current->visited++;
        }
        current->word_end++;
    }

    void deleteWord(string word) {

        Node* current = this->root;
        string :: iterator left = word.begin();
        string :: iterator right = word.end();

        current->visited--;

        for (left; left != right; left++) {
            int x = *left - offset;

            if (!current->son[x])
                return;

            current = current->son[x];
            current->visited--;
        }

        current->word_end--;
        if (current->word_end < 0)
            current->word_end = 0;

    }

    int getLongestPrefix(string word) {

        Node* current = this->root;
        string :: iterator left = word.begin();
        string :: iterator right = word.end();

        int lg = 0;

         for (left; left != right; left++) {
            int x = *left - offset;

            if (!current->son[x])
                return lg;

            current = current->son[x];
            if (!current->visited)
                return lg;

            lg++;
         }

         return lg;
    }

    int countWords() {
        return this->nr_words;
    }
};

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

int main() {

    Trie myTrie;

    int task;
    string S;

    while (fin >> task >> S) {
        switch (task) {
            case 0:
                myTrie.insertWord(S);
                break;

            case 1:
                myTrie.deleteWord(S);
                break;

            case 2:
                fout << myTrie.countAparitions(S) << "\n";
                break;

            case 3:
                fout << myTrie.getLongestPrefix(S) << "\n";
                break;
        }
    }

    return 0;
}