#include <bits/stdc++.h>
using namespace std;
ifstream in ( "trie.in" );
ofstream out ( "trie.out" );
struct nod
{
    int info,cate;
    nod *urm[26], *prec;
    /*nod() {
        info = 0;
        memset ( urm, 0, sizeof ( urm ) );
        memset ( prec, 0, sizeof ( prec ) );
    }*/
};
nod* prim;
void adaug ( nod* &first, string s )
{
    if ( first == NULL )
    {
        first = new nod;
        first->info =first->cate= 0;
        for ( int i = 0; i < 26; i++ )
            first->urm[i] = NULL;
        first->prec=NULL;
    }
    nod *aux = first;
    for ( int i = 0; i < s.size(); i++ )
    {
        if ( aux->urm[s[i] - 'a'] == NULL )
        {
            nod *aux2 = new nod;
            aux2->info=0;
            aux2->cate=1;
            for(int k=0; k<26; k++)
                aux2->urm[k]=NULL;
            aux->urm[s[i] - 'a'] = aux2;
            aux2->prec= aux;
            aux = aux2;
            for ( int j = i + 1; j < s.size(); j++ )
            {
                aux2 = new nod;
                aux2->info = 0;
                aux2->cate=1;
                for ( int k = 0; k < 26; k++ )
                    aux2->urm[k] = NULL;
                aux2->prec=aux;
                aux->urm[s[j] - 'a'] = aux2;
                aux = aux2;
            }
            break;
        }
        else
        {
            aux = aux->urm[s[i] - 'a'];
            aux->cate++;
        }
    }
    aux->info++;
}
void scoate ( nod* &first, string s )
{
    nod *aux = first;
    for ( int i = 0; i < s.size(); i++ )
        aux = aux->urm[s[i] - 'a'];
    if ( aux->info >= 2 )
    {
        aux->info--;
        for(int i=s.size()-1; i>=1; i--)
        {
            aux->cate--;
            aux=aux->prec;
        }
    }
    else
    {
        nod *aux2;
        for(int i=s.size()-1;i>=1&&aux->cate==1;i--)
        {
         aux2=aux->prec;
         aux2->urm[s[i]-'a']=NULL;
         delete(aux);
         aux=aux2;
        }
        while(aux!=first)
        {
         aux->cate--;
         aux=aux->prec;
        }
    }
}
void afiseaza ( nod* &first, string s )
{
    nod *aux = first;
    for ( int i = 0; i < s.size()&&aux!=NULL; i++ )
        aux = aux->urm[s[i] - 'a'];
    if(aux!=NULL)
        out << aux->info << '\n';
    else
        out<<"0\n";
}
void prefix ( nod* &first, string s )
{
    nod *aux = first;
    int cnt = 0,i=0;
    for ( ; i < s.size() && aux != NULL; i++ )
        aux = aux->urm[s[i] - 'a'];
    if(aux!=NULL)
        out<<s.size()<<'\n';
    else
        out<<i-1<<'\n';
}
string s, s0;
int main()
{
    int t;
    //prim = new nod();
    for(string s; in>>t;)
    {
        in>>s;
        if ( t == 0 )
            adaug ( prim, s );
        else if ( t == 1 )
            scoate ( prim, s );
        else if ( t == 2 )
            afiseaza ( prim, s );
        else
            prefix ( prim, s );
    }
    return 0;
}