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

const int nr_lit = 'z'-'a'+1;
struct trie {
        trie    *p[nr_lit];
        int             value;
        trie() { value = 0; memset(p, 0, sizeof(p)); }
} root;

void add( char* );
void del( char* );
void ask( char* );
void wtf( char* );

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

        while ( !feof(stdin) ) {
                int op;
                char buf[32];
                scanf( "%d %s\n", &op, buf );
                switch ( op ) {
                        case 0: add( buf ); break;
                        case 1: del( buf ); break;
                        case 2: ask( buf ); break;
                        case 3: wtf( buf );
                }
        }
        return 0;
}

void add( char *s ) {
        trie *p = &root;
        int n = strlen( s );
        for ( int i=0; i<n; p = p->p[ s[i++]-'a' ] )
                if ( p->p[ s[i]-'a' ] == NULL )
                        p->p[ s[i]-'a' ] = new trie();
        p -> value ++;
}

void cleanup( trie *p, char *s, int i, int n ) {
        if ( i==n ) return;
        cleanup( p->p[ s[i]-'a' ], s, i+1, n );
        bool ok = true;
        for ( int l = 0; l<nr_lit; ++l )
                if ( p->p[ s[i]-'a']->p[l] != NULL )
                        ok = false;
        if ( ok && p->p[ s[i]-'a']->value==0 ) {
                delete p->p[ s[i]-'a'];
        p->p[ s[i]-'a' ] = NULL;
    }
}

void del( char *s ) {
        trie *p = &root;
        int n = strlen( s ), tmp[32];
        for ( int i=0; i<n; p = p->p[ s[i++]-'a' ] ) {
                if ( p->p[ s[i]-'a' ] == NULL )
                        return;
                tmp[i] = p->value;
        }
        p -> value --;

        cleanup( &root, s, 0, n );
}

void ask( char *s ) {
        trie *p = &root;
        int n = strlen( s );
        for ( int i=0; i<n; p = p->p[ s[i++]-'a' ] )
                if ( p->p[ s[i]-'a' ] == NULL )
                        return;
        printf( "%d\n", p->value );
}

void wtf( char *s ) {
        trie *p = &root;
        int n = strlen( s ), i;
        for ( i=0; i<n; p = p->p[ s[i++]-'a' ] )
                if ( p->p[ s[i]-'a' ] == NULL )
                        break;
        printf( "%d\n", i );

}