#include <fstream>
#include <string>
#include <iostream>
#include <vector>
#include <string.h>

using namespace std;

struct Trie {
    int cnt, child_cnt;
    Trie * child[26];
    Trie() {
        cnt = child_cnt = 0;
        memset(child, 0, sizeof(child));
    }
};

Trie *T = new Trie;

void add_word(Trie *nod, const char *s);
int del_word(Trie *nod, const char *s);
int count_word(Trie *nod, const char *s);
int max_prefix(Trie *nod, const char *s, int len);
void print_trie(Trie *nod, int offset, char c);

int main()
{
    ifstream f ("trie.in");
    ofstream g ("trie.out");
    int t;
    string s;
    while (f >> t)
    {
        f >> s;
        switch(t) {
            case 0: add_word(T, s.c_str()); break;
            case 1: del_word(T, s.c_str()); break;
            case 2: g << count_word(T, s.c_str()) << '\n'; break;
            case 3: g << max_prefix(T, s.c_str(), 0) << '\n'; break;
        }
    }
//    print_trie(T, 2, '#');
    return 0;
}

void add_word(Trie *nod, const char *s) // done!
{
    if (*s == '\0')
    {
        (nod->cnt)++;
        return;
    }
    else
    {
        int i = *s - 'a';
        if (nod->child[i] == 0)
        {
            nod->child[i] = new Trie;
            nod->child_cnt ++;
        }
        add_word(nod->child[i], s+1);
    }
}

int count_word(Trie *nod, const char *s) // done!
{
    if (*s == '\0')
        return nod->cnt;
    int i = *s -  'a';
    if (nod->child[i])
        return count_word(nod->child[i], s+1);
    return 0;
}

int max_prefix(Trie *nod, const char *s, int len) // done!
{
    if (*s == '\0')
        return len;
    int i = *s - 'a';
    if (nod->child[i] == 0)
        return len;
    return max_prefix(nod->child[i], s+1, len+1);
}

int del_word(Trie *nod, const char *s)
{
    if (*s == '\0')
    {
        nod->cnt --;
    }
    else
    {
        int i = *s - 'a';
        if (del_word(nod->child[i], s+1))
        {
            nod->child_cnt --;
            nod->child[i] = 0;
        }
    }
    if (nod->cnt == 0 && nod->child_cnt == 0 && nod != T)
    {
        delete nod;
        return 1;
    }
    return 0;
}

void print_trie(Trie *nod, int offset, char c) // done!
{
    cout << string(offset, ' ') << c << ": " << nod->cnt << '\n';
    if (nod->child_cnt == 0)
        return;
    else for (int i = 0; i < 26; i++)
    {
        if (nod->child[i] != 0)
        {
            print_trie(nod->child[i], offset + 2, i + 'a');
        }
    }
}