#include <fstream>
#include <cstring>

#define CH (*s - 'a')
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");

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 == NULL ) {
        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 == NULL )
        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 == NULL )
        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 == NULL || nod->fiu[ CH ] == 0 )
        return k;
    return pre( nod->fiu[ CH ], s+1, k+1 );
}

int main()
 {
    char line[ 32 ];
    while(f.getline(line,32))
    {
        if(line[0]==NULL) break;
        switch( line[0] ) {
            case '0': ins( T, line+2 ); break;
            case '1': del( T, line+2 ); break;
            case '2': g<<que( T, line+2 )<<'\n'; break;
            case '3': g<<pre( T, line+2, 0 )<<'\n'; break;
        }
    }
    return 0;
}