#include <fstream>
#include <string>
using namespace std;
const int NrCar='z'-'a'+1;
class trie{
  public:
   int nr_words,nr_sons;
   trie *leg[NrCar];
   trie(){
     nr_words=nr_sons=0;
     memset(leg,0,sizeof(leg));
     }
   void add(string word);
   int search(string word);
   void erase(string word);
   int prefix(string word);
   };
void trie::add(string word){
     int i;
     trie *r=this;
     for (i=0;i<(int)word.length();++i){
         if (!r->leg[word[i]-'a'])
          r->leg[word[i]-'a']=new trie();
         r=r->leg[word[i]-'a'];
         r->nr_sons++;}
     r->nr_words++;
     }
int trie::search(string word){
    int i;
    trie *r=this;
    for (i=0;i<(int)word.length();++i){
        if (!r->leg[word[i]-'a']) return 0;
        r=r->leg[word[i]-'a'];}
    return r->nr_words;
    }
int trie::prefix(string word){
    int i;
    trie *r=this;
    for (i=0;i<(int)word.length();++i){
        if (!r->leg[word[i]-'a']) return i;
        r=r->leg[word[i]-'a'];}
    return i;
    }
void trie::erase(string word){
     int i;
     trie *r=this,*aux;
     for (i=0;i<(int)word.length();++i){
         if (!r->leg[word[i]-'a']) return;
         aux=r;
         r=r->leg[word[i]-'a'];
         r->nr_sons--;
         if (aux->nr_sons==0) delete aux;
         else 
         if (r->nr_sons==0) aux->leg[word[i]-'a']=0;
         }
     r->nr_words--;
     if (r->nr_sons==0) delete r;
     }

ifstream f("trie.in");
ofstream g("trie.out");
string s,word;
trie *t=new trie();
int main(){
    t->nr_sons=1;
    while (!f.eof()){
      getline(f,s);
      if (s.length()<3) continue;
      word=s.substr(2,s.length()-2);
      switch (s[0]){
        case '0': t->add(word);break;
        case '1': t->erase(word);break;
        case '2': g<<t->search(word)<<'\n';break;
        case '3': g<<t->prefix(word)<<'\n';break;
        };
      }
    return 0;
}