#include <cstdio>
#include <cstring>
using namespace std;

struct Trie {
    Trie * next[ 27 ];
    int terminal;
    int cnt, nr_fi;
    Trie () {
        memset( next, 0, sizeof( next ) );
        cnt = nr_fi = terminal = 0;
    }
};

void Insert ( Trie * node, char * s );
int QueryAparitii ( Trie * node, char * s );
int Delete ( Trie * node, Trie * root, char * s );
int QueryPrefix ( Trie * node, char * s, int nivel );


int main () {

    freopen("trie.in","r",stdin);
    freopen("trie.out","w",stdout);

    int k;
    char s[ 100 ];
    Trie * root = new Trie;

    while ( scanf( "%d%s",&k,s ) != EOF ) {
        if ( k == 0) {
            Insert( root, s );
        } else if ( k == 1 ) {
            Delete( root, root, s );
        } else if ( k == 2 ) {
            printf( "%d\n",QueryAparitii( root, s ) );
        } else {
            printf( "%d\n",QueryPrefix( root, s, 0 ) );
        }
    }

    return 0;

}

void Insert ( Trie * node, char * s ) {
    if ( *s == 0 ) {
        node -> terminal = 1;
        node -> cnt++;
        return ;
    }
    if ( !node -> next[ * s - 'a' ] ) {
        node -> next[ * s - 'a' ] = new Trie;
        node -> nr_fi++;
    }
    Insert( node -> next[ *s - 'a' ], s + 1 );
}

int QueryAparitii ( Trie * node, char * s ) {
    if ( !node ) return 0;
    if ( *s == 0 ) return node -> cnt;
    return QueryAparitii( node -> next[ *s - 'a' ], s + 1 );
}

int Delete ( Trie * node, Trie * root, char * s ) {
    if ( *s == 0 ) {
        node -> cnt--;
    } else if ( Delete( node -> next[ *s - 'a' ] , root, s + 1 ) ) {
        node -> next[ *s - 'a' ] = 0;
        node -> nr_fi--;
    }
    if ( node -> cnt == 0 && node -> nr_fi == 0 && node != root ) {
        delete node;
        return 1;
    }
    return 0;
}

int QueryPrefix ( Trie * node, char * s, int nivel ) {
    if ( *s == 0 || !node -> next[ *s - 'a' ] ) return nivel;
    return QueryPrefix( node -> next[ *s - 'a' ], s + 1, nivel + 1 );
}