#include <fstream>
#include <cstring>

using namespace std;

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

int c,caz;
char w[30];

struct nod {
    int prefix;
    int cuvinte;
    nod *v[26];
    nod ()
    {
        for (int i=0;i<26;i++)
        v[i] = NULL;
        prefix = 0;
        cuvinte = 0;
    }
} *arb, *p, *aux;

void adauga(char s[30])
{
    p = arb;
    int len = strlen(s);
    for (int i=0;i<len;i++)
    {
        c = s[i] - 'a';
        if (p->v[c] == NULL)
            p->v[c] = new nod();
        p = p->v[c];
        if (i == len-1)
            p->cuvinte ++;
        p->prefix ++;

    }
}

void sterge(char s[30])
{
    p = arb;
    int len = strlen(s);
    for (int i=0;i<len;i++)
    {
        c = s[i] - 'a';
        aux = p;
        p = p->v[c];
        if (i == len-1)
            p->cuvinte --;
        p->prefix --;
        if (p->prefix == 0)
        {
            delete(p);
            aux->v[c] = NULL;
            return;
        }

    }
}

void pfx(char s[30])
{
    p = arb;
    int len = strlen(s);
    for (int i=0;i<len;i++)
    {
        c = s[i] - 'a';
        if (p->v[c] == NULL)
        {
            fout<<i<<"\n";
            return;
        }
        p = p->v[c];
    }
}

void cuv(char s[30])
{
    p = arb;
    int len = strlen(s);
    for (int i=0;i<len;i++)
    {
        c = s[i] - 'a';
        if (p->v[c] == NULL)
        {
            fout<<"0\n";
            return;
        }
        p = p->v[c];
    }
    fout<<p->cuvinte<<"\n";
}



int main()
{
    arb = new nod();
    while(fin>>caz)
    {
        fin>>w;
        if (caz == 0)
            adauga(w);
        if (caz == 1)
            sterge(w);
        if (caz == 2)
            cuv(w);
        if (caz == 3)
            pfx(w);
    }
    return 0;
}