#include <fstream>
#define c (*S - 'a')

using namespace std;

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

struct Trie
{
    int ap, nrs;
    Trie * Son[26];

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

        for(int i = 0; i < 26; i++)
            Son[i] = 0;
    }
};

Trie * Root = new Trie;

bool Delete(Trie * & Nod, char S[])
{
    if(*S) {
        if(Delete(Nod -> Son[c], S + 1))
            Nod -> nrs--, Nod -> Son[c] = 0;
    }
    else Nod -> ap--;

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

void Insert(Trie * & Nod, char S[])
{
    if(*S) {
        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 == 0) return Nod -> ap;

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

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

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

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

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

int main()
{
    char p, W[21];

    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;
}