/* 
 * File:   main.cpp
 * Author: virtualdemon
 *
 * Created on May 8, 2010, 1:07 PM
 */
#include <cstdlib>
#include <fstream>

/*
 * 
 */
using namespace std;
typedef char* str;
class trie
{
    trie* t[30];
    int CountAp, CountSons;
    bool IsNC( char x )
    {
        return x < 'a' || x > 'z';
    }
public:
    trie( void ) : CountAp(0), CountSons(0)
    {
        for( int i=0; i < 30; ++i )
            t[i]=NULL;
    }
    inline void Add( str );
    inline bool Del( str );
    inline int CountWords( str );
    inline int MaxPrefix( str, int& );
} *root;
inline void trie::Add( str s )
{
    if( IsNC(s[0]) )
    {
        ++this->CountAp;
        return;
    }
    int c=s[0]-'a';
    if( NULL == this->t[c] )
        this->t[c]=new trie, ++this->CountSons;
    this->t[c]->Add( s+1 );
}
inline bool trie::Del( str s )
{
    if( IsNC(s[0]) )
    {
        --this->CountAp;
        if( 0 == this->CountAp && 0 == this->CountSons && root != this )
        {
            delete this;
            return true;
        }
        return false;
    }
    int c=s[0]-'a';
    --this->CountAp;
    if( this->t[c]->Del(s+1) )
    {
        --this->CountSons;
        this->t[c]=NULL;
    }
    if( 0 == this->CountAp && 0 == this->CountSons && root != this )
    {
        delete this;
        return true;
    }
    return false;
}
inline int trie::CountWords( str s )
{
    if( IsNC(s[0]) )
        return this->CountAp;
    int c=s[0]-'a';
    if( NULL == this->t[c] )
        return 0;
    return this->t[c]->CountWords(s+1);
}
inline int trie::MaxPrefix( str s, int& l )
{
    if( IsNC(s[0]) )
        return l;
    int c=s[0]-'a';
    if( NULL == this->t[c] )
        return l;
    ++l;
    return this->t[c]->MaxPrefix( s+1, l );
}
char s[30];
int main(int argc, char** argv)
{
     int i;
     ifstream in( "trie.in" );
     ofstream out( "trie.out" );
     root=new trie;
     while( in>>i>>s )
     {
         if( !i )
             root->Add(s);
         else if( 1 == i )
                 root->Del(s);
              else if( 2 == i )
                      out<<root->CountWords(s)<<'\n';
                   else i=0, out<<root->MaxPrefix( s, i )<<'\n';
     }
     return (EXIT_SUCCESS);
}