#include <iostream>
#include <fstream>
#include <unordered_map>

using namespace std;

class TrieNode
{
public:
    TrieNode()
    {
        this->endingHere = 0;
        this->prefixCount = 0;
        this->children = {};
    }

    void add(string word)
    {
        auto current = this;

        for (auto it = word.begin(); it != word.end(); ++it)
        {
            auto node = &current->children[*it];
            current->children[*it] = *node;
            current->prefixCount++;
            current = node;
        }

        current->prefixCount++;
        current->endingHere++;

        // cout << word << " -> " << current->endingHere << endl;
    };

    void remove(string word)
    {
        auto current = this;

        for (auto it = word.begin(); it != word.end(); ++it)
        {
            current->prefixCount--;
            current = &current->children[*it];
        }

        current->prefixCount--;
        current->endingHere--;

        // cout << word << " -> " << current->endingHere << endl;
    }

    int count(string word)
    {
        auto current = this;

        for (auto it = word.begin(); it != word.end(); ++it)
        {
            current = &current->children[*it];
        }

        return current->endingHere;
    }

    int prefix(string word)
    {
        auto current = this;
        int prefix = 0;

        for (auto it = word.begin(); it != word.end(); ++it)
        {
            auto node = current->children.find(*it);
            if (node != current->children.end() && node->second.prefixCount > 0)
            {
                prefix++;
                current = &node->second;
            }
            else
            {
                break;
            }
        }

        return prefix;
    }
    // TrieNode();
    // void add(string word);
    // void remove(string word);
    // int count(string word);
    // int prefix(string word);

private:
    int endingHere;
    int prefixCount;
    unordered_map<char, TrieNode> children;
};

int main()
{
    ios_base::sync_with_stdio(false);
    freopen("trie.in", "r", stdin);
    freopen("trie.out", "w", stdout);

    int query;
    string word;

    TrieNode trie;

    while (cin >> query)
    {
        cin.ignore(1);
        getline(cin, word);

        if (query == 0)
        {
            trie.add(word);
        }
        else if (query == 1)
        {
            trie.remove(word);
        }
        else if (query == 2)
        {
            cout << trie.count(word) << '\n';
        }
        else
        {
            cout << trie.prefix(word) << '\n';
        }
    }

    return 0;
}

// TrieNode::TrieNode()
// {
//     this->endingHere = 0;
//     this->prefixCount = 0;
//     this->children = {};
// }

// void TrieNode::add(string word)
// {
//     auto current = this;

//     for (auto it = word.begin(); it != word.end(); ++it)
//     {
//         auto node = &current->children[*it];
//         current->children[*it] = *node;
//         current->prefixCount++;
//         current = node;
//     }

//     current->prefixCount++;
//     current->endingHere++;

//     // cout << word << " -> " << current->endingHere << endl;
// };

// void TrieNode::remove(string word)
// {
//     auto current = this;

//     for (auto it = word.begin(); it != word.end(); ++it)
//     {
//         current->prefixCount--;
//         current = &current->children[*it];
//     }

//     current->prefixCount--;
//     current->endingHere--;

//     // cout << word << " -> " << current->endingHere << endl;
// }

// int TrieNode::count(string word)
// {
//     auto current = this;

//     for (auto it = word.begin(); it != word.end(); ++it)
//     {
//         current = &current->children[*it];
//     }

//     return current->endingHere;
// }

// int TrieNode::prefix(string word)
// {
//     auto current = this;
//     int prefix = 0;

//     for (auto it = word.begin(); it != word.end(); ++it)
//     {
//         auto node = current->children.find(*it);
//         if (node != current->children.end() && node->second.prefixCount > 0)
//         {
//             prefix++;
//             current = &node->second;
//         }
//         else
//         {
//             break;
//         }
//     }

//     return prefix;
// }