#include <fstream>
#include <unordered_map>
#include <memory>
#include <string>

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


struct Node {
    std::unordered_map<char, std::unique_ptr<Node>> letters;
    int freq = 0;

    void addWord(const std::string& word) {
        Node* node = this;
        for (char c : word) {
            auto& next = node->letters[c];
            if (!next)
                next = std::make_unique<Node>();
            node = next.get();
        }
        node->freq++;
    }

    bool eraseWord(const std::string& word, int i = 0) {
        if (i == (int)word.size()) {
            freq--;
        } else {
            auto it = letters.find(word[i]);
            if (it == letters.end())
            return false;
            if (it->second->eraseWord(word, i + 1))
                letters.erase(it);
        }
        return freq == 0 && letters.empty();
    }

    int count(const std::string& word) {
        Node* node = this;
        int n = word.size();
        for (int i = 0; i < n; i++) {
            if (node->letters.find(word[i]) == node->letters.end()) {
                return 0;
            }
            node = node->letters[word[i]].get();
        }
        return node->freq;
    }

    int getPrefix(const std::string& word) {
        Node* node = this;
        int n = word.size();
        for (int i = 0; i < n; i++) {
            if (node->letters.find(word[i]) == node->letters.end()) {
                return i;
            }
            node = node->letters[word[i]].get();
        }
        return n;
    }
};

int main() {

    Node* trie = new Node{};
    int op;
    std::string word;
    while (fin >> op >> word) {
        if (op == 0) {
            trie->addWord(word);
        } else if (op == 1) {
            trie->eraseWord(word);
        } else if (op == 2) {
            fout << trie->count(word) << '\n';
        } else if (op == 3) {
            fout << trie->getPrefix(word) << '\n';
        }
    }

    return 0;
}