#include <fstream>

using namespace std;

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

const int SMax = ('z' - 'a' + 5);

int p; char W[25];

struct Trie
{
    int ap, nrs;
    Trie * Son[SMax];

    Trie(){
        ap = 0, nrs = 0;

        for(int i = 0; i < SMax; i++)
            Son[i] = 0;
    }
};

bool Delete(Trie * & Nod, char S[])
{
    bool a;

    if(*S == '\0')
    {
        Nod -> ap--, a = false;

        if(!(Nod -> ap) && !(Nod -> nrs))
        {
            a = true;
            delete Nod;
        }
        return a;
    }
    else
    {
        char c = *S - 'a';
        a = Delete(Nod -> Son[c], S + 1);

        if(a) Nod -> nrs--, Nod -> Son[c] = 0;

        if(a && !(Nod -> nrs))
        {
            delete Nod;
            return 1;
        }
        return 0;
    }
}

void Insert(Trie * & Nod, char S[])
{
    if(*S) {
        char c = *S - 'a';

        if(Nod -> Son[c] == 0)
        {
            Nod -> Son[c] = new Trie;
            Nod -> nrs++;
        }
        Insert(Nod -> Son[c], S + 1);
    }
    else
        Nod -> ap++;
}

int Aparitii(Trie * Nod, char S[])
{
    if(*S) {
        char c = *S - 'a';

        if(Nod -> Son[c] == 0)
            return 0;

        return Aparitii(Nod -> Son[c], S + 1);
    }
    else
        return Nod -> ap;
}

int Prefix(Trie * Nod, char S[], int lev)
{
    if(*S == '\0')
        return lev;

    char c = *S - 'a';

    if(Nod -> Son[c] == 0)
        return lev;

    return Prefix(Nod -> Son[c], S + 1, lev + 1);
}

Trie * Root = new Trie;

int main()
{
    while(fin >> p) {
        fin >> W;

        if(p == 0)
            Insert(Root, W);
        else if(p == 1)
            Delete(Root, W);
        else if(p == 2)
            fout << Aparitii(Root, W) << '\n';
        else
            fout << Prefix(Root, W, 0) << '\n';
    }

    fin.close();
    fout.close();

    return 0;
}