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

using namespace std;

class Trie;

class Node {
private:
    short counter;
    short words;
    map<char, Node*> v;
public:
    Node();
    ~Node();

    friend class Trie;
};

Node::Node() {
    words   = 0;
    counter = 0;
}

Node::~Node() {
    for (auto it : v) {
        delete it.second;
    }
}

class Trie {
private:
    Node* root;

public:
    Trie();
    ~Trie();

    void  add(string& s);
    void  remove(string& s);
    short search(string& s);
    short prefix(string& s);
};

Trie::Trie() {
    root = new Node();
}

Trie::~Trie() {
    delete root;
}

void Trie::add(string& s) {
    auto node = root;
    for (auto it : s) {
        auto& v  = node->v;
        if (v.find(it) == v.end())
            v[it] = new Node();
        node = v[it];
        node->counter++;
    }

    node->words++;
}

void Trie::remove(string& s) {
    auto node = root;
    for (auto it : s) {
        auto& v = node->v;
        if ( v.find(it) == v.end())
            return;
        if (--v[it]->counter == 0) {
            delete v[it];
            v.erase(it);
            return;
        }
        node = v[it];
    }
    node->words--;
}

short Trie::search(string& s) {
    auto node = root;
    for (auto it : s) {
        auto& v = node->v;
        if ( v.find(it) == v.end())
            return 0;
        node = v[it];
    }
    return node->words;
}

short Trie::prefix(string& s) {
    auto node = root;
    short result = 0;
    for (auto it : s) {
        auto& v = node->v;
        if ( v.find(it) == v.end())
            return result;
        if (v[it]->counter == 0)
            return result;
        result++;
        node = v[it];
    }
    return result;
}

int main(int argc, char const *argv[]) {

    Trie problem;

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

    char n;
    string s;

    while (in>>n) {
        in>>s;
        switch (n) {
            case '0' :
                problem.add(s);
                break;
            case '1' :
                problem.remove(s);
                break;
            case '2' :
                out<<problem.search(s)<<"\n";
                break;
            case '3' :
                out<<problem.prefix(s)<<"\n";
                break;
            default:
                break;
        }
    }

    return 0;
}