#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");
int c;
char cuv[21];
struct trie
{
    int cuv, prefixe;
    trie* litere[30];

    trie()
    {
        cuv = 0;
        prefixe = 0;
        for (int i = 0; i < 30; i++)
            litere[i] = 0;
    }
};
void adaugare(trie* rad, char* cuv, int poz)
{
    rad->prefixe++;
    if (strlen(cuv) == poz)
    {
        rad->cuv++;
        return;
    }
    int litera = cuv[poz] - 'a';
    if (rad->litere[litera] == 0)
         rad->litere[litera] = new trie;
       adaugare(rad->litere[litera], cuv, poz + 1);
}
void stergere(trie* rad, char* c, int poz)
{
    rad->prefixe--;
    if (poz == strlen(c))
    {
        rad->cuv--;
        return;
    }

    /// gasim litera din cuvantul de sters si continuam stergerea
    int litera = c[poz] - 'a';
    stergere(rad->litere[litera], c, poz + 1);
}

int nr_aparitii(trie* rad, char* cuv, int poz)
{
    if (strlen(cuv) == poz)
    {
        return rad->cuv;
    }
    int litera = cuv[poz] - 'a';
    if (rad->litere[litera] == 0 || rad->litere[litera]->prefixe == 0)
        return 0;
    nr_aparitii(rad->litere[litera], cuv, poz + 1);
}
int max_prefix(trie* rad, char* cuv, int poz)
{
    if (strlen(cuv)==poz)
    {
        return strlen(cuv);
    }
    int litera = cuv[poz] - 'a';
    if (rad->litere[litera] == 0 || rad->litere[litera]->prefixe == 0)
        return poz;
    max_prefix(rad->litere[litera], cuv, poz + 1);
}
int main()
{
    int op;
    char ch[21];
    trie* rad = new trie;
    while (f >> op >> ch)
    {
        switch (op)
        {
        case 0:
            adaugare(rad, ch, 0);
            break;
        case 1:
            stergere(rad, ch, 0);
            break;
        case 2:
            g << nr_aparitii(rad, ch, 0) << '\n';
            break;
        case 3:
            g << max_prefix(rad, ch, 0) << '\n';
            break;
        }
    }

}