#include <iostream>
#include <fstream>

using namespace std;
const int SIGMA = 26;
const int MAX_SIZE = 20;
const char FIRST = 'a';
const int BOS = 0;

char input[1 + MAX_SIZE];
struct trie {
   int frecv_word, prefix;
   trie* children[SIGMA];
   trie () {
       frecv_word = prefix = 0;
       for ( int letter = 0; letter < SIGMA; letter ++ )
          children[letter] = NULL;
   }
};
void add_to ( trie* root, char* my_string ) {
   if ( *my_string != NULL ) {
     if ( root -> children[*my_string - FIRST] == NULL )
       root -> children[*my_string - FIRST] = new trie;
     root = root -> children[*my_string - FIRST];
    root -> prefix ++; add_to ( root, my_string + 1 );
   }
   else
     root -> frecv_word ++;
}
void delete_at ( trie* root, char* my_string ) {
   if ( *my_string != NULL ) {
     root = root -> children[*my_string - FIRST];
     root -> prefix --;
     delete_at ( root, my_string + 1 );
   }
   else
     root -> frecv_word --;
}
int count_in ( trie* root, char* my_string ) {
   if ( *my_string == NULL )
     return root -> frecv_word;
   if ( root -> children[*my_string - FIRST] == NULL )
     return 0;
   if ( root -> children[*my_string - FIRST] -> prefix == 0 )
     return 0;
   return count_in ( root -> children[*my_string - FIRST], my_string + 1 );
}
int LCP ( trie* root, char *my_string, int steps ) {
   if ( root -> children[*my_string - FIRST] == NULL )
     return steps;
   if ( root -> children[*my_string - FIRST] -> prefix == 0 )
     return steps;
   return LCP ( root -> children[*my_string - FIRST], my_string + 1, steps + 1 );
}
ifstream fin ( "trie.in" );
ofstream fout ( "trie.out" );
int main()
{
    trie* root = new trie;
    int op;
    while ( fin >> op >> input ) {
      switch ( op ) {
      case 0:
        add_to ( root, input );
        break;
      case 1:
         delete_at ( root, input );
         break;
      case 2:
        fout << count_in ( root, input ) << "\n";
        break;
      case 3:
        fout << LCP ( root, input, BOS ) << "\n";
        break;
      }
    }
    return 0;
}