#include <fstream>
#include <string>
#define ch (s[poz]-97)
using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
string s;
struct Trie
{
    int cuv,sons;
    Trie *fii[30];
    Trie()
    {
        cuv = sons = 0;
        for(int i = 0; i < 26; i++)
            fii[i] = NULL;
    }
};
Trie *T;
int op;

void insert(Trie *&nod, int poz)
{
    if(nod == NULL)
        nod = new Trie();
    if(poz == s.size())
    {
        nod->cuv++;
    }
    else
    {
        nod->sons++;
        insert(nod->fii[ch], poz+1);
    }
}
void del(Trie *&nod, int poz)
{
    if(poz == s.size())
    {
        nod->cuv--;
    }
    else
    {
        nod->sons--;
        del(nod->fii[ch], poz+1);
    }
    if(nod->cuv + nod->sons == 0)
        delete nod,nod = NULL;
}
int aparitii(Trie *&nod, int poz)
{
    if(nod == NULL)
        return 0;
    if(poz == s.size())
        return nod->cuv;
    else
        return aparitii(nod->fii[ch], poz+1);
}
int prefix(Trie *&nod, int poz)
{
    if(poz == s.size())
        return poz;
    if(nod->fii[ch] != NULL && (nod->fii[ch]->cuv || nod->fii[ch]->sons) )
        return prefix(nod->fii[ch], poz+1);
    return poz;
}
int main()
{
    T = new Trie();
    while(fin >> op)
    {
        fin >> s;
        if(op == 0)
            insert(T,0);
        if(op == 1)
            del(T,0);
        if(op == 2)
            fout<<aparitii(T,0)<<'\n';
        if(op == 3)
            fout<<prefix(T,0)<<'\n';
    }
    return 0;
}