#include <fstream>
#include <stdio.h>

using namespace std;

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

class Node
{
public:
    int nr_a = 0;
    int nr_c = 0;

    Node* fii[26] {nullptr};
};

class Trie
{
    Node* root = nullptr;
public:

    void insert(char* s)
    {
        root = insert_(s, root);
    }

    void erase(char* s)
    {
        root = erase_(s, root);
    }

    int query_prefix(char* s)
    {
        return query_prefix_(s, root);
    }

    int query_cuvant(char* s)
    {
        return query_cuv_(s, root);
    }


private:
    int query_prefix_(char* s, Node* node);
    int query_cuv_(char* s, Node* node);
    Node* insert_(char* s, Node* node);
    Node* erase_(char* s, Node* node);
};

Node* Trie::insert_(char* s, Node* node)
{
    if(node == nullptr)
    {
        node = new Node();
    }

    node->nr_a++;

    if(s[0] == '\0')
    {
        node->nr_c++;
        return node;
    }
    else
    {
        node->fii[s[0] - 'a'] = insert_(s + 1, node->fii[s[0] - 'a']);
    }

    return node;
}

Node* Trie::erase_(char* s, Node* node)
{
    if(node == nullptr)
    {
        return node;
    }

    node->nr_a--;

    if(s[0] == '\0')
    {
        node->nr_c--;
    }
    else
    {
        node->fii[s[0] - 'a'] = erase_(s + 1, node->fii[s[0] - 'a']);
    }

    if(node->nr_a == 0)
    {
        delete node;
        node = nullptr;
    }
    return node;
}

int Trie::query_prefix_(char* s, Node* node)
{
    if(s[0] == '\0' || node == nullptr || node->fii[s[0] - 'a'] == nullptr)
        return 0;

    return query_prefix_(s + 1, node->fii[s[0] - 'a']) + 1;

}

int Trie::query_cuv_(char* s, Node* node)
{
    if(node == nullptr)
    {
        return 0;
    }
    else if(s[0] == '\0')
        return node->nr_c;
    else
        return query_cuv_(s + 1, node->fii[s[0] - 'a']);
}

Trie arbore;
char s[25];

int main()
{
    freopen("trie.in", "r", stdin);
    freopen("trie.out", "w", stdout);
    
    while(in.getline(s, 25))
    {     
        switch(s[0])
        {
            case '0':
                arbore.insert(s + 2);
                break;
            case '1':
                arbore.erase(s + 2);
                break;
            case '2':
                out<<arbore.query_cuvant(s + 2)<<"\n";
                break;
            case '3':
                out<<arbore.query_prefix(s + 2)<<"\n";
                break;
        }
    }
}