#include <cstdio>
#include <cstring>

#define LMAX 30

using namespace std;

struct nod
{
    nod *L[26];
    int CateCuv, CatiFii;
    nod()
    {
        memset( L, 0, sizeof(L) );
        CateCuv = CatiFii = 0;
    }
};

nod *R;
int Tip, LC;
char Cuv[LMAX];

inline void Adauga( nod *NOD, char *lit )
{
    if( *lit == '\n' )
    {
        ++(NOD -> CateCuv);
        return;
    }
    if( NOD -> L[*lit - 'a'] == 0 )
    {
        NOD -> L[*lit - 'a'] = new nod;
        ++(NOD -> CatiFii);
    }

    Adauga( NOD -> L[*lit - 'a'], lit+1 );
}

inline int Scoate( nod *NOD, char *lit )
{
    if( *lit == '\n' ) --(NOD -> CateCuv);
    else if( Scoate( NOD -> L[*lit - 'a'], lit+1 ) )
    {
        NOD -> L[*lit - 'a'] = 0;
        --(NOD -> CatiFii);
    }

    if( NOD -> CateCuv == 0 && NOD -> CatiFii == 0 && NOD != R )
    {
        delete NOD;
        return 1;
    }

    return 0;
}

inline int NrAparitii( nod *NOD, char *lit )
{
    if( *lit == '\n' ) return NOD -> CateCuv;
    if( NOD -> L[*lit - 'a'] ) return NrAparitii( NOD -> L[*lit - 'a'], lit+1 );

    return 0;
}

inline int LGLCP( nod *NOD, char *lit, int Lg )
{
    if( *lit == '\n' || NOD -> L[*lit - 'a'] == 0 ) return Lg;
    return LGLCP( NOD -> L[*lit - 'a'], lit+1, Lg+1 );
}

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

    R = new nod;

    while( fgets( Cuv, LMAX, stdin ) )
        switch( Cuv[0] )
        {
            case '0':
                Adauga( R, Cuv+2 );
                break;
            case '1':
                Scoate( R, Cuv+2 );
                break;
            case '2':
                printf("%d\n", NrAparitii( R, Cuv+2 ));
                break;
            case '3':
                printf("%d\n", LGLCP( R, Cuv+2, 0 ));
                break;
        }

    return 0;
}