#include <fstream>
#include <algorithm>
#include <cstring>

using namespace std;

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

const int NMAX  = 100000;
const int SIGMA = 26;

struct Trie {
    int cnt, nrf;
    Trie *fiu[SIGMA];

    Trie() {
        cnt = nrf = 0;
        for( int i = 0;  i < SIGMA;  ++i ) {
            fiu[i] = NULL;
        }
    }
};

Trie *Trie_Root = new Trie;
int Ans_prefix = 0;

///   #Trie
int CH( char ch ) {
    return ( (int)(ch - 'a') );
}

void Insert( Trie *nod, char *s ) {
    if( *s == '\0' ) {
        nod->cnt++;
        return ;
    }
    if( nod->fiu[ CH(*s) ] == NULL ) {
        nod->fiu[ CH(*s) ] = new Trie;
        nod->nrf++;
    }
    Insert( nod->fiu[ CH(*s) ] , s+1 );
}

int Delete( Trie *nod, char *s ) {
    if( *s == '\0' ) {
        nod->cnt--;
    }
    else if( Delete( nod->fiu[ CH(*s) ], s+1 ) ) {
        nod->fiu[ CH(*s) ] = NULL;
        nod->nrf--;
    }

    if( nod->cnt == 0 && nod->nrf == 0 && nod != Trie_Root ) {
        delete nod;
        return 1;
    }
    return 0;
}

int Query( Trie *nod, char *s ) {
    if( *s == '\0' ) {
        return nod->cnt;
    }
    if( nod->fiu[ CH(*s) ] ) {
        return ( Query( nod->fiu[ CH(*s) ] , s+1 ) );
    }
    return 0;
}

int Prefix( Trie *nod, char *s, int lg ) {
    if( *s == '\0' || nod->fiu[ CH(*s) ] == NULL ) {
        return lg;
    }
    return Prefix( nod->fiu[ CH(*s) ] , s+1, lg+1 );
}

int main() {
 ///   Trie_Root -> cnt = 1;

    char str[30];
    memset( str, 0, sizeof(str) );
    int op = 0;
    while( in >> op ) {
        memset( str, 0, sizeof( str ) );
        in >> str;

        if( op == 0 ) {  ///  ADAUGARE
            Insert( Trie_Root, str );
        }
        else if( op == 1 ) {  ///  STERGERE
            Delete( Trie_Root, str );
        }
        else if( op == 2 ) {  ///  DE CATE ORI
            out << Query( Trie_Root, str ) << '\n';
        }
        else if( op == 3 ) {  ///  CEL MAI LUNG PREFIX
            out << Prefix( Trie_Root, str, 0 ) << '\n';
        }
    }
    return 0;
}