#include <fstream>

using namespace std;

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

struct trie{
    int fii,nr;
    trie *f[26];
    trie (){
        fii = nr = 0;
        for (int i=0;i<26;i++)
            f[i] = 0; /// trebuie sa initializam cu 0

    }

};
trie *root = new trie;
char s[25];
int c;
void insertTrie (trie *rad, char *s){
    if (*s != 0){
        if (rad->f[*s - 'a'] == 0){
            rad->f[*s - 'a'] = new trie;
            rad->fii++;
        }
        insertTrie (rad->f[*s-'a'],s+1);

    } else
        rad->nr++;

}

int deleteTrie (trie *&rad, char *s){
    if (*s == 0){
        rad->nr--;
        if (rad->nr == 0 && rad->fii == 0 && rad != root){
            delete rad;
            rad = NULL;
            return 1;
        }

    } else{
        if ( deleteTrie (rad->f[*s-'a'],s+1 ) ){
            rad->fii --;
            if (rad->fii == 0 && rad->nr == 0 && rad != root){
                delete rad;
                rad = NULL;
                return 1;
            }
        }

    }
    return 0;

}

int queryTrie (trie *rad,char *s){
    if (*s == 0)
        return rad->nr;

    if (rad->f[*s-'a'] == NULL)
        return 0;

    else
        queryTrie(rad->f[*s-'a'],s+1);

}

int prefix (trie *rad, char *s){
    if (*s == 0)
        return 0;
    if (rad->f[*s-'a'] == NULL)
        return 0;
    else
        return 1 + prefix (rad->f[*s-'a'],s+1);
}

int main (){

    while (fin>>c>>s){
        if (c == 0) /// adauga o aparitie a cuvantului s in lista
            insertTrie(root,s);

        else{
            if (c == 1) /// sterge o aparitie a cuvantului s din lista
                deleteTrie(root,s);

            else{
                if (c == 2) /// tipareste numarul de aparitii al cuvantului s
                    fout<<queryTrie(root,s)<<"\n";

                else    /// tipareste lungimea celui mai lung prefix comun al lui s cu orice cuvant din lista
                    fout<<prefix (root,s)<<"\n";

            }
        }

    }

    return 0;
}