#include <cstring>
#include <cstdio>
#define CH (*s - 'a')
using namespace std;
struct Trie
{
    int cnt, nrfii;
    Trie *fiu[ 26 ];
    Trie()
    {
        cnt = nrfii = 0;
        memset( fiu, 0, sizeof( fiu ) );
    }
};

Trie *T = new Trie;
void ins( Trie *nod, char *s )
{
    if( *s == '\n' )
    {
        nod->cnt ++;
        return;
    }
    if( nod->fiu[ CH ] == 0 )
    {
        nod->fiu[ CH ] = new Trie;
        nod->nrfii ++;
    }
    ins( nod->fiu[ CH ], s+1 );
}
int del( Trie *nod, char *s )
{
    if( *s == '\n' )
        nod->cnt --;
    else if( del( nod->fiu[ CH ], s+1 ) )
    {
        nod->fiu[ CH ] = 0;
        nod->nrfii --;
    }

    if( nod->cnt == 0 && nod->nrfii == 0 && nod != T )
    {

        delete nod;
        return 1;
    }
    return 0;
}
int que( Trie *nod, char *s )
{
    if( *s == '\n' )
        return nod->cnt;
    if( nod->fiu[ CH ] )
        return que( nod->fiu[ CH ], s+1 );
    return 0;
}
int pre( Trie *nod, char *s, int k )
{
    if( *s == '\n' || nod->fiu[ CH ] == 0 )
        return k;
    return pre( nod->fiu[ CH ], s+1, k+1 );
}
int main()
{
    char line[ 32 ];
    freopen( "trie.in", "r", stdin );
    freopen( "trie.out", "w", stdout );
    fgets( line, 32, stdin );
    while( !feof( stdin ) )
    {
        switch( line[0] )
        {
        case '0':
            ins( T, line+2 );
            break;
        case '1':
            del( T, line+2 );
            break;
        case '2':
            printf( "%d\n", que( T, line+2 ) );
            break;
        case '3':
            printf( "%d\n", pre( T, line+2, 0 ) );
            break;
        }
        fgets( line, 32, stdin );
    }
    return 0;
}